My iClever BK20 is keep pressing Left Option Key in background automatically...i check it in https://en.key-test.ru/ website.
I think because of it keyboard is not behaving properly and is typing weird characters and symbols. 

I tried all the methods i found in the forum but of no use. Like, reseting the bluetooth and FN+SHIFT + BACKSPACE key for 5 sec etc.

How to fix? 

Thanks!