Repairing iPhone displays is very expensive if you don’t have AppleCare+. The iPhone X display alone costs $279. The iPhone 8 and 8 Plus is much more doable, but still pricey at $149 and $169 respectively. That’s assuming you’re going through Apple to do the repair.

The cheapest solution is to go through third-party repair services that will charge much less. Unfortunately, you may run the risk of getting a faulty display. Multiple users are reporting third-party repairs of their iPhone display is cutting out the functionality of the ambient light sensor. This means the display won’t adjust the brightness of the display automatically.

In nearly every case—it doesn’t matter if the repairs were done with genuine Apple parts—the sensor is still bricking out. During these repairs, the sensor is not even being replaced or tampered with, yet it’s still experiencing issues.

According to Engadget, the culprit for the issue is iOS 11. It’s not entirely clear if the disabling of the ambient sensor is being done on purpose by Apple or a rogue bug.

Even more troubling, Motherboard is reporting iPhone 8 and 8 Plus models that have had their display repaired by third-party shops have seen the touch functionality stop working on their devices.

“This has caused my company over 2,000 reshipments,” related a shop repair owner to Motherboard. “Customers are annoyed and it seems like Apple is doing this to prevent customers from doing 3rd party repair.”

This specific bug seems to be related to the most recent iOS 11.3 update. A microchip in the display is disabled with the update thus the non-responsive displays. Third-party repair services have managed to find a fix, but that involves re-opening the phone and upgrading the chip.

Apple seems to be forcing users to go through its repair services rather than third-party services. If you opt to go with the latter, you risk annoying issues like the ambient sensor or touch capability being disabled from your iPhone. It’s unfortunate Apple has embarked on this path of pettiness and something to keep in mind should the need to repair your iPhone display comes up.