Blender Viewport Posing Lag (<1 FPS)

Hey all — I’m hoping someone here can help me diagnose this weird lag I’m getting in Blender. I often download fully rigged character models from sites like Sketchfab. When I import them, they look fine. But the moment I switch to pose mode — even when doing something simple — the viewport becomes unusable: 3 to 5 frames per second max, bone-movement is jittery/stuttery, sometimes selection or moving takes a second or two before the model visibly deforms.

For reference, here are my PC specs: I’m using a MSI “Thin 15.6″ FHD 144Hz Gaming Laptop” with an Intel Core i5-13420H CPU and an NVIDIA GeForce RTX 4050 laptop GPU (6 GB VRAM), at 40 GB DDR4 RAM and a standard SSD.

According to the specs, this should be more than capable of handling 3D animation or posing rigs