Superfish menus UI distort intermittently

I use superfish at several sites and don't have this problem

I believe we are experiencing the same issue, albeit extremely intermittently:

Clearing the caches immediately fixes the issue for at least 2 days; but it inevitably crops up again, albeit inconsistently. (Unfortunately, it's always the client who lets us know there's an issue, and it's always after hours, of course!)

While we haven't tried disabling aggregation yet, we have tried disabling Redis, as it seems this happens when it's at its maximum size. I'll report back to let you know if this works...