No, I haven't. I do also have Chrome. Haven't used FireFox in ages. Next time it happens I try and remember to use another browser and see if it helps.
@djsfantasi I just recently set Edge to clear every time I exit the app. This has been happening intermittently for a while. At odd hours and when it happens and it persists for hours. Not a daily occurrence but varies and usually at least twice in a week, sometimes more and sometimes less. I leave my computer running so it can do automated and unattended updates and leave the browser open with a few apps idling (mail, facebook, AAC). It may run for days without closing Edge or rebooting. Running 64bit Win10 Home OS on an Alienware Aurora R6 w/ 32Gb of memory. Enormous amount of capacity and typically much less than half used. Currently 6 apps, 138 background processes using 25% of I7-7700 quad-core CPU @ 3.7GHz and 29% of memory.
Again, every time I click on Forum I am logged out and taken to forum. This is annoying. It seems to happen a couple of times for hours at a time every month.