After the issues with Paranoid Android, I could not revert to the OS the device came with and I am now on OxygenOS 5.0.8, which I downloaded from the official OnePlus website. I have been observing weird and annoying bugs, e.g., in GoogleMaps the settings page can be partially seen on the left, trying to kick in without succeeding. Mostly in GoogleMaps at times the keyboard tends to write by itself. In a few occasions the app became unusable. The keyboard thing happened on another app as well. Once when I tried to call the WiFi setting page, the Bluetooth one kept opening. Sometimes, after pressing the bottom right button I am unable to close apps by dragging them left or right out of the display. When the device behaves in an irresponsive way or does things by itself, I have occasionally seen flashes along lines on the display.
All these things do not happen all the time, and often a device reboot is not necessary to make problems (temporarily) disappear. It is kind of random. I checked and found several complaints from users on GoogleMaps and keyboard, but in none exactly my issues are reported.
I wonder whether all these problems are caused by a non-clean flashing of the ROM after I messed around with PA.
To be honest, I used the phone as it came only for minutes before attempting to flash PA, so I can't say how it worked as received.
Today, without wanting, I got all the Google Apps updated, and the keyboard problem occurred once within 30 min usage.
Any suggestion? Have other OxygenOS users observe similar things in the past, before moving to PA? Can it be a "bad" phone? I could upgrade to Pie, and see what happens (and how the eyestrain evolves).
Sorry, I do not want to use this forum for purposes different from eyestrain. I consider it an appendix to the bad install of PA. Thanks in advance for any insight!