The difference in screen size between the secondary screen and regular phone sizes can cause software compatibility issues.
Thank you for your support of Xiaomi products. All phones undergo rigorous professional inspection before leaving the factory, so you can use them with confidence. The touch issues you're encountering with specific APPs are likely due to third-party APP compatibility issues. When you encounter such problems, please promptly submit feedback specifying the problematic APP. Xiaomi engineers will push third-party APPs to complete the adaptation as soon as possible to solve the problem.