I have this problem with an 8gib 2080. Nvidia drivers have bugs with Wayland or Vulkan which is at least partially a memory leak.

Here’s one for example: https://forums.developer.nvidia.com/t/kwin-6-7-x-causes-mass...

Just search KWin Nvidia memory leak or Wayland Nvidia memory leak or kwin wayland Nvidia memory leak. It’s constantly issues and I remain convinced some intermixing of the two + monitors is at fault.