Yes, Apple broke legacy screensavers when multiple monitors are present, even
some of their own screensavers. We just have to wait for them to fix it. It's
been reported, and I've heard that they are aware.
https://discussions.apple.com/thread/254745941
Steve via iPad
I think macOS 13.3 screen saver is easily confused.
I'm using the stock photo wall saver on a 2019 Intel 32GB 2TB MBP with 3
4k monitors. (Which really slows a wired network connection down!)
At first (just after the update), one monitor said "No Pictures" while
the other two showed
With the latest upgrade to macOS 13.3,
I have received a few reports from users that my screensaver (a real .saver)
looks funny when the Mac has two monitors, the built-in one and an external one.
Symptoms:
it does not show anything on the builtin monitor, as if it's not running on
that one.
