On my Samsung Galaxy S6 (Android 6.0.1), sometimes the back button starts firing by itself, hence closing the current app or going back on a page. Other times it's like a ghost press on other parts of the screen, so that e.g. the menu opens by itself. Often this happens in bursts, making the device unusable.
It's a common problem, as seen here:
Users report as possible causes:
Use of data connection (perhaps causing #1)
Hardware problem (interference from speakers on the capacitive touchscreen)
Moisture (triggering false contacts on the capacitive touchscreen)
In my case, I've noticed it happening especially when I use the Twitter app, which makes large use of the phone capabilities. Running Smart Manager and closing all running apps sometimes solves the issue, so it might really be #1.
Users suggest possible solution (none of which are working):
Factory reset and/or cache reset
Let device cool down
Disable data and/or WiFi connection
Lower volume speakers to less than 75% (?)
Dial *#2663# and do a TSP FW Update (General)
Anyone found a definitive fix for it?
I've had this happen to me on 2016 (hence the post), then the problem disappeared by itself, now in 2019 it's back, more annoying than ever.
Note: Related to an older Galaxy model: Galaxy S4 back button pressing itself