UPDATE FROM MY END:
I upgraded my Desktop PC - motherboard & CPU to a new Ryzen 9600x.
(By the way - I did this repair above with two separate desktop machines with similar hardware, because they were having the same D2R issue in 2025 with W11).
I went with Windows 10 this time instead of Windows 11, and like magic, this game works just like it did in year 2024 and prior.
I played like this for a week no issues, and then I experimented by accepting Microsoft’s Windows 11 free upgrade.
Guess what happened? D2R started running like complete crap again, just like it did back with my old intel i5-14400F CPU. So I reverted back to Windows 10, and no more issues.
Can you please fix this game ? At least I found a solution to your game being gimped, but I cannot run Windows 10 forever due to the OS being soon abandoned.
Windows 10 is losing support in exactly 4 months!!!