Try adjusting the response time in the Display Menu in the OSD - on my lg monitor text appears much better when this is set to low - it looks like your screenshot when set to high. Doesn't affect anything else as far as I can tell. Might be worth playing with the ULMB setting as well if not...
Try a virtual machine running Discus under windows 7. Use virtual box or similar.
I use an xp virtual machine to run an old 16bit label printing programme and it works ok on my win 11 machine.
All motherboard manufacturers chipset drivers installed? Monitor .inf file installed?
No hardware specs in your computer showing so can't help much more.