All extensions disabled due to expiration of intermediate signing cert

So:

  * Started day with browser, no problems with extensions
  * At some point in the afternoon, all extensions disappeared
  * A couple of hours (cannot be more specific I am afraid), all extensions came back

However I'm noticing the saved preferences of some of the extensions has gone. e.g. Password manager has kept the username however all "Multi-account containers" are now reset to factory defaults.

Is anybody seeing similar behaviour ?

Yep, there's a bug open for that: https://bugzilla.mozilla.org/show_bug.cgi?id=1549013