@Simlcs I found the exact same topic here https://community.tp-link.com/en/home/forum/topic/249420 It was locked with no response. It is scandalous that an update can just break your device, I'll buy...

I did the software update on my tp link app, my extender did a reset and now the power LED is ON, but it's impossible to connect to the tp link wi fi, the reset button doesn't work either.