I know this is a long shot but i bricked my X5 Air last night and spent hours trying to get back on ( screen was locked with Finow logo ) . This is what worked :-
Hold bottom button then hold middle button at same time . Let go of middle button when menu appears . Then let go off bottom button
In menu there is a section saying " Clear … " . Clear this then reboot from menu .
I then left watch for about twenty minutes and it factory reset and came back on ? No idea how …
Hope it works
Thanks