Keyboard and mouse unresponsive seconds after screenlock on XFCE and kernel 5.10

Using XFCE and this happened after switching kernels.
One of my snap applications doesn’t work anymore on kernel 5.4, so as per advice on this forum I switched to 5.10.

I get the feeling this is not directly connected to the screenlock,
because the “freeze” does not happen directly,
but around 3 seconds after the screenlock.
I’m able to manually screenlock without a problem.

Also, switching from light-locker to xfce-screensaver did not help, nor did turning off the screenlock on xfce-screensaver.