changes to screensaver stop taking effect

[bressucli2]

Fedora 30
Mate 1.22.1
mate-screensaver 1.22.1-1

Alright, so I'll start by describing my use case ... I have "Blank screen" configured by default, but when particular notifications (such as for e-mail) happen while the screen is locked, I have a script that switches the screensaver to "Pop art squares" -- this is so that I can see at a glance when walking by my computer if there are any notifications, without having to stop and log in.

The script activates "Pop art squares" as follows:
gsettings set org.mate.screensaver mode 'single';
gsettings set org.mate.screensaver themes "['screensavers-popsquares']";
mate-screensaver-command --cycle;

Whenever the screen is unlocked, the screensaver is set back to the default "Blank screen" as follows:
gsettings set org.mate.screensaver mode 'blank-only';
gsettings set org.mate.screensaver themes "[]";

This has worked beautifully for a long time, until I switched from Fedora 28 to Fedora 30 ... in Fedora 30, it all works correctly for a while, but changes to the screen saver eventually stop taking effect. Once this happens, changes to the screensaver even in mate-screensaver-preferences don't take effect, regardless of which screensaver is chosen. The screensaver choice is saved (if I close mate-screensaver-preferences and come back, it shows the correct screensaver, or if I look in dconf editor, it shows as correct), but the configured screensaver doesn't get used.

There isn't any issue previewing the screensavers in mate-screensaver-preferences, they just don't get used when the screensaver is activated.

The issue continues until I log out and log back in, at which point things work again for a while.

I will be very happy to do troubleshooting and answer any questions to help to identify the problem. It's really frustrating for me right now because I can't rely upon my notification system :-/

[bressucli2]

While the screen is locked and showing a blank screen, I pull up a Ctrl-Alt-F2, log-in, and run the following commands, with the following outputs:
gsettings get org.mate.screensaver mode;
'single'
gsettings get org.mate.screensaver themes;
['screensavers-popsquares']

I also input the following commands with non-anomalous results:
mate-screensaver-command --query
The screensaver is active
The screensaver is not inhibited
mate-screensaver-command --time
The screensaver has been active for 38 seconds

Running the following command does not address the issue:
mate-screensaver-command --cycle

After running the following commands and then locking the screen, the correct screensaver will be shown:
pgrep mate-screensave
1640
kill -9 1640
mate-screensaver