I'm having a weird problem with Neverwinter Nights Diamond Edition. It randomly freezes for up to 20 to 30 seconds but if I alt tab out of the game it unfreezes immediately. Most of the time this happens in loading screens but it is not limited to loading screens and happens elsewhere as well.

I'm plaing on 1.69 Critical rebuild with NWShader. I have tried using only the base GOG installation but that doesn't solve the problem. I'm using W11, RX 6800 XT, Ryzen 5 5600X, 32GB RAM.

What could be the issue here? Has anyone had a similar problem?