[Warner306]

anyone figured out how to get rid of the gui lag when opening videos?

No, as stated previously, this lag cannot be completely eliminated due to the frame buffer used by madVR. This is a compromise of this software.

but i'm not using madvr

Then it's likely Kodi's fault. You could be a little more helpful when asking for help. Each post spills out into four or five one line responses that ends in no resolution to your problem. Give some details about what you are doing and what settings are being used in these circumstances.