Mate Screensaver Issue on ~Current

I'm using the Mate spin. The order of events was:

1. Build a mate spin Liveslak USB
2. Install to clean drives using the setup2hd script
3. Upgrade with current of 2024-03-24.
4. Locally mirror the Mate packages (base, deps, extra) from the msb directory on slackware.uk
5. Upgrade mate with them.
6. Repeat the last three steps with current of 2024-03-30 over this xz backdoor thing. I needn't have bothered.

On current of 2024-03-24, I could turn off the pc from the system menu in Mate, but on current of 2024-03-30, I can't. I can only log off, which Mate won't let me do if anything is running. Then I get back into sddm, which has kill & reboot buttons.

Also on current of 2024-03-24, there were two screensavers which argued. So I uninstalled one, left and set up xscreensaver. But it never comes on. I have it set for 10 minutes, and of course it doesn't interrupt zoom. But on current of 2024-03-30, after 5 minutes, the screen goes dark and the monitor powers off. It shuts down zoom, and kills the sound. Undoing that takes 15-29 seconds and I typically get 7 or so notices saying this, that & the other have gone, and then been found again :banghead:

Mate archives are all dated March 31st, so I gather I have the newest ones. Does anyone have similar issues?