Input method editor (IME) selection box not showing?

[emz911]

Hi! I've been making a game in Chinese where users get to input their name, but a majority of them cannot see the IME selection box when inputting, which makes it hard to choose the correct word/character they want, they can only press 123 blindly.
Example of what it should look like (selection box present):

FF2F9A2E-1177-4E79-85A7-A3B22D92F895.png (13.58 KiB) Viewed 4469 times

What some people get (selection box is hidden):

BDF04AB1-60F7-4276-9295-DF3147E624C4.png (6.75 KiB) Viewed 4469 times

Wild guess: maybe the engine's screen is placed in front of the IME screen, covering it?
I also wonder if the issue has to do with the OS or the user's unique keyboard (there are a lot of different IME keyboards to download), but currently I cannot replicate it with a Mac nor a PC (Alienware) using the default keyboard, Baidu IME or Sogou IME, though I do know that more than half of my users have this problem.
Any help would be greatly appreciated! Thank you!
(Sorry for double posting but I'm not quite sure which forum this thread best fits in)