5 Big Problems Users Are Already Having With The iPhone Duo

The iPhone Duo, Apple's first foldable iPhone, has been out for a few days now — and the pre-orders are already delayed till 2027. While early customers have been enjoying a fresh new take on the iPhone almost a decade after the company truly refreshed its smartphone design, they're also facing several problems that one wouldn't expect to experience on a $1,999 phone. Among the biggest problems users are facing with the iPhone Duo are ongoing reports of inner display cracking, unoptimized apps, and increasing heat during certain tasks.

Apple isn't the first brand to deal with first-gen issues related to foldable phones. Brands like Samsung and Google also faced similar issues with their debut folding phones, but Apple always sets its customers' expectations higher. Even though Apple created a clever solution for the hinge mechanism along with the nano-texture layer to hide the crease, users are still experiencing certain issues, and here are the most annoying ones reported by users.

While Android manufacturers give an estimate of how many times their smartphones can be folded, Apple just says its iPhone Duo is built to last. However, several publications reported issues that early adopters have experienced with the device's internal screen. Several users said they heard the hinge of the iPhone making a crunch sound, only to discover that the inner panel had a large crack in the center of the crease, with part of the right side of the display also breaking.

In a report, iFixit suggested a few possible scenarios for what could have happened: a localized mechanical stress caused by overlapping internal support edges near the central hinge, a joint of the hinge momentarily getting stuck or not articulating smoothly, or friction or misalignment preventing the ultrathin layers of the iPhone Duo from gliding freely over those structural edge transitions, leading to micro-fractures on the display.

Whatever the real issue is, Apple told Bloomberg's Mark Gurman that it's "aware of an issue impacting the inner display on a small number of iPhone Duo units," and that customers should reach out to Apple representatives, as they will handle the situation. So far, the company is not treating this issue as a widespread problem, but instead as something only a few people have encountered.

While Apple was trying to prepare developers for an all-new display ahead of the official announcement of the iPhone Duo, the reality is rather different. Don't get us wrong — there are apps already optimized for the iPhone Duo. But the truth is that most commonly used apps, like social media portals, banking apps, games, and other productivity apps, still remain unoptimized.

For those unoptimized apps, Apple uses black bars that take up a large section of the display. This ruins the experience of using the iPhone Duo. At this moment, some developers are also just increasing the amount of space their apps occupy on the Duo while they work on preparing an optimized version. Truth be told, even Apple needs to catch up with its stock apps, as not every app from the company has been properly optimized for the narrower outer display and the huge inner screen of the Duo. Safari, for instance, takes up a lot of space on the bottom and the right side of the phone, leading to less content being displayed compared to a standard iPhone.

Just like the iPhone 18 Pro models, Apple added its revamped vapor chamber cooling system to the iPhone Duo. The new vapor chamber sits on top of the powerful A20 Pro chip to send heat away from it, which helps improve sustained peak performance, display brightness, and even battery life. On paper, this makes it seem like the iPhone Duo is the perfect device for gaming, video editing, and heavy multitasking. However, users have been noticing that the iPhone Duo can get really hot to the touch.

In a Reddit thread, a user talks about how hot the iPhone Duo got while on a wireless charger, even though they were using it with a case and with "barely any activity." In the same thread, another Redditor said: "My Duo is running very hot. I've just sat at my lunch scrolling through Twitter, and the phone is roasting hot; I can feel the heat through the hard case, and the screen is even hot." While some users point to the iPhone likely indexing data and optimizing Siri as a possible issue, others point to the fact that the vapor chamber is actually working. As one Redditor explains, "This is what happens with a heat spreader, and why the heat extends to the full half of the phone where the A20 Pro is. The same happens with the iPhone 18 Pro phones; the chip stays cooler, but it's a little less comfortable to hold."

Possibly one of the worst problems of the iPhone Duo is its cameras. The device features four cameras: A 12MP selfie camera in the outer display, an under-display 4MP shooter on the inner display, and a 48MP primary shooter accompanied by an ultra-wide lens. According to reviewers and customers, the main selfie camera and the primary shooter are usable, especially in good lighting conditions. After all, none of the sensors are the same as the ones available on the iPhone 18 Pro, or even the iPhone 17 from last year. Even though the photos are 'acceptable', what's unacceptable is the really premium price that customers are paying for Apple's most innovative phone, but without the best features.

For most customers who have owned a Pro iPhone before, the main issue is the lack of a telephoto lens. On a Reddit thread, a user said, "The biggest downside is the lack of telephoto, but the sensor is good enough." On a different thread, another user comments on the lack of telephoto: "The main and wide cameras are still pretty solid. Zoom, obviously, is pretty bad on this device once you exceed the 2x." Regarding the inner 4MP camera, most reviewers just agree that it's okayish for a FaceTime call, but even that can be a stretch, especially with the other cameras available.

Last but not least, one concern every iPhone user has is iOS 27 bugs. While early claims suggested that iOS 27 would be all about Siri AI and fixing bugs, it seems like Apple still needs a lot more time to polish the system. With an all-new iPhone, new display possibilities, and new ways to interact with the phone, it's only natural that the recently released iOS 27.2 is still somewhat buggy for this device.

Mashable, for example, says some apps get the camera orientation wrong, Apple's own software can get confused depending on how you're using the foldable, and even smaller things like random accidental touches can make the experience worse. On Reddit, people noted that influencers and journalists reviewing the iPhone Duo had some UI issues, which is something we expect Apple to fix over time, but it's always important to highlight, as we're talking about a very expensive device.

Developer Christian Selig, for example, highlighted issues he has been experiencing with the iPhone Duo's weird Dynamic Island and with important parts of the UI on the right side of the phone; everything in that area can look incorrect. More interestingly, he points to developers who updated their apps for iOS 27 but, obviously, didn't know about the iPhone Duo displaying Live Activities on the phone in a weirder way. Fortunately, this can all be solved in future software updates.