I have similar experience with extended monitor setup:
if I turn off the primary (left) monitor - and then turn it on again: everything on my right monitor moves to my primary monitor.
However if I turn off and on my second non primary (right) monitor everything stays as it was.
This annoying because even if I normally never turn off any of my monitors, starting a full screen game on my primary left monitor it goes black for a short time while loading the game and when it comes back all my windows, browser, etc. on my second monitor moves to my primary monitor. In that case I have to Alt +Tab out of the game and manually move my other windows back to my right second monitor.
My Rig:
GPU: ASUS TUF Gaming AMD Radeon RX 6900 XT OC 16GB
Adrenalin s/w: 21.10.2
Extended monitor setup: Gigabyte AORUS-FI27Q27" 2560x1440 @165Hz (primary), Philips IPS 24" 1920x1080 @60Hz.
Mobo: Asus ROG Crosshair VIII Hero (wi-fi) with AMD X570 chipset
BIOS ver. 3801 (with AGESA V2 PI 1.2.0.3 Patch C).
Chipset: amd_chipset_software_3.09.01.140
SAM: Enabled and fully functional.
CPU: AMD Ryzen 9 3950X
Ram: Corsair Vengeance low profile 16GB @3200 MHz cl16
CPU Cooler: Noctua NH-D15-Se AM4
Storage: M2 Samsung 980 Pro 2TB NWME, SSD Samsumg 950 Pro 1 TB SATA
Windows 10 Pro 21H1 with latest Windows optional update.
Best regards from Sweden