@ChrisM Welcome to the forum!
I agree that the behavior that you and @64bit have described in this thread is different from the general performance degradation described in GitHub Issue #12286 and the corresponding community forum thread.
Basically, there is nothing wrong with the overall performance of the extension, it is just that when unlocking, the extension UI initially hangs, displaying only a spinning circle:
This “spinning circle” state persists indefinitely if no action is taken, but can be fixed at will by simply closing the browser extension window and then re-opening it (or by popping out the extension window). When the extension window is re-opened (or popped out), then the UI for the unlocked vault is immediately displayed, with no lingering performance degradation.
I am currently observing this in extension version 2025.1.3, in Chrome 132.0.6834.160, but I don’t recall exactly when this started.
Interestingly, the behavior seems to be reproducible in the browser extension pop-up, but if the browser extension window is popped out before unlocking, then the spinning circle problem does not occur.