mi5 screen turns off after I touch the home button / fingerprint reader On my MI5, if I touch the fingerprint reader on the home button, the 
screen turns off. Then for 5-10 seconds nothing happens, and afterwards I can click the ON button, which shows the lock screen once again.

It appears that others have hit a similar issue with the screen turning on: XDA post, MIUI forum post.

Questions:


How can I stop this from happening?
I don't use the fingerprint reader. Is there a way to disable the reader completely? The only ways I found require either root and fiddling with system files (miui post above, StackExchange question), or applying duct tape.


More details:


This started just now, not after any specific action (didn't update/install/etc)
I don't have, and never had, any password/pin/drawing/fingerprint - I only slide the lockscreen up to unlock the phone.


I tried setting a pin, and also pin+fingerprint - same behavior

I've set "sleep after" to "never"
Device: Xiaomi MI 5, Android 6.0.1 MXB48T, MIUI Global 8.1|stable 8.1.2.0(MAAMIDI), baseband TH20c1.9-00055, core version 3.18.20-perf-gfacbe79
Turns out that the device's screen was defective (because of a fall an a bad replacement job). I had the screen replaced, and now the issue doesn't happen anymore.