Depending on your location and your triggers, my solution may not be helpful.
In my case, I can't find any relief on any LED monitors, whether it's supposedly flicker-free or or full of anti-blue light filters. Therefore, I depend on the refurbished market of old CCFL-backlit monitors. I managed to buy Dell 2209WA, 2009WT, and now I'm even looking for old CCFL 120Hz monitors for gaming, and Dell U2410 for work. Where I live in France, such refurbished market is quite strong, so I have many opportunities to find them. Even old 4:3 screens coming from companies or my friends and family are usable for me. They are not the "sexiest" screens out there but I can't complain, they are perfect for secondary monitors.
With CCFL monitors, I've been able to use W7, W10 with all versions (1809, 1909, latest 2HXX versions), and many Linux OS. I can work and play with them all day long with no issues.
I'm willing to try modern monitors like the ones described in this thread, but I already can't find any new phones and buying and sending them back is already tiring for me. I'll wait for such monitors