Hi @MCYV567,
Welcome to the Premiere Pro forums and thank you for reporting a problem.
What is the RAM allocation for Premiere Pro under Preferences > Memory? Is this happening with specific projects or media, or can you see this happening in an empty project?
Do you have any third-party plugins or panels installed? Even if FX are muted, are there any specific effects applied?
Sorry for the frustration,
Dani