After login with a new user (that i had created before) it worked, i tried login with my user and worked but had a couple of kwin crashes
I think it could be due my setup being a laptop + 2 externals screens, but the laptop screen is disabled, when I logged in it was active (having 3 screens enabled) and when I lay down the laptop screen it crashed again...
This usually is a case of incompatible plasmoids/themes with latest Plasma (also make sure pacman -Qm doesn't show packages that need rebuild or are incompatible).
Im using default dark breeze with a couple of custom plasmoids, i'll try deleting those
Not related, but there is no need to downgrade PHP like you did, php7 is available and can be installed alongside php. php packages
Oh didn't know! I downgraded because I had to make a change in a legacy project that was incompatible with 8.1 and had some urgency 😅