Screen lock broken after waking up form suspend

I'm using FreeBSD 13 with KDE on a Thinkpad T460.

When I wake up the laptop from suspend by opening the lid, I briefly see the login screen, before the screen goes fully black with a message saying: "Screen lock is broken" then something to the extend that I should switch to a different VT to enter a command to fix it. However switching to a different VT doesn't work and I have to do a cold restart.

How can I start debugging this? Anyone familiar with the issue?