This just happens yesterday.
When I click any add-on dropdown menu, it shown up for like a second then disappear.
I tried to disable the hardware acceleration, but it still happens.
Now all of the add-ons that need to click to use like bitwarden are all unusable.
Please help,
I found the culprit.
I hook a Nintendo Switch Pro Controller via a usb cable to my machine.
And it constantly detecting another USB device on and off. So the drop down menu keep disappearing.
Very weird behavior.