Thanks for the reply.
Console logins are fine. They're accessible with Alt_F1-Alt_F6.
Most window managers have one screen where you minimize applications, but xfce has 4, which you access with Ctrl_F1-Ctrl_F4. Of those, I only have 2:-(. That was my problem.
As this is an update it resided on an sdcard of my RazPi 4. I bit the bullet and updated my SSD.
I purposely left out the /etc/ directory with all the configuration stuff. I have a working backup of the SSD if I need it. This solved the issue
. I also kept the /home/myuser directory unchanged.
There's all these little tweaks in both places, and I put them in, like them, but forget completely what I did. Slackware is sufficiently stable, and I'm such a creature of habit that I rarely have to bother updating the configs.