Screen freezing and not going to sleep

[ndrwum]

Screen does not turn off when putting mac to sleep both manually and timed sleep.

Using Macbook Pro M1 Max on MacOS Ventura 13.2 (22D49) with Sceptre ‎E275B-QPN168 external monitor.
Tried checking dummies sleep workaround checkbox on and off. Tried using all combinations in the dummies section in the advanced settings.

[waydabber]

You should use dummies only as a last resort to get HiDPI and scaling (dummies are useful for other stuff though), only if native smooth scaling does not work for some reason. Otherwise you'll encounter issues like this (see known issues). Since these are mostly macOS level bugs/issues, there is no stable way to fix them, only some workarounds that tend not to work properly. :(