Premiere Beta 26.3 Windows - Extremely slow menu bar and effect controls keyframe performance

I am experiencing hangs and very slow performance when Interacting with the menu bar (file / edit / clip / sequence etc) as well as when manipulating keyframes in the Effects Control Panel.

When interacting with those elements, Premiere will hang for anywhere between a few seconds to multiple dozens of seconds, and the cursor will change to a ‘busy’ icon. The application window sometimes also ‘greys out.’ Windows itself will sometimes become unreponsive during these hangs preventing me from switching applications or interacting with the start menu.

This issue occurs when any project is open, including new empty projects. It does not occur when a project is not currently open.

During these hangs, I notice that Premiere is loading a single thread on my system to 100%, which ends when the program becomes responsive again. The hangs are clearly visible in this process explorer graph below:

There are no other noticable increases on system load; memory, GPU activity, and I/O are appear normal.

Running the beta with administrator privileges prevents the issue from occuring, and the above pattern of CPU resource usage does not occur.

Other trouble shooting steps attempted:

• Unmapping all mounted network shares and rebooting
• Running Premiere with Windows Explorer closed
• Adjusting Windows power plan settings
• Updating GPU drivers to latest available
• Disabling hardware accelerated GUI rendering
• Resetting preferences

The menu bar related symptoms sound very similar to this CC2026 bug report, however I can not replicate the issue in 2026:

System specificaitons:

• Premiere Beta 26.3 (issue occured on previous Beta versions too)
• Windows 11 Pro 25H2 build 26200.8457
• Nvidia GTX 1070, Studio driver 581.87
• Intel i5-13600k, iGPU driver 32.0.101.708
• 64GB RAM
• ASUS XG-C100C 10G NIC

Update:

I’ve narrowed it down to another application - Malwarebytes. The issue immediately goes away if Malwarebytes is closed from the system tray.