Express just stops working ???

[aroby1]

So today, my wife started working on a page in her Chrome browser.  She used the Elements feature on the left hand icon bar.  All worked fine.  Later on, this just stopped working.  Select Elements and nothing happens.  So she asked me if I have something blocked on the network.  No, I don't!  I tried it on my machine in Firefox.  Same thing, Elements doesn't work.  Pull up Microsoft Edge, it works fine.

What is going on???

[Imaginerie]

I just tried on my machine (Firefox, Edge and Chrome) and all work as intended for me.
Is there any pop-up blocker or that kind of things on the non-working browsers?
This is what I got in Edge

and this is what I got in Firefox

Is there a particular set of action that lead to it not working?
Was the cloud symbol showing a syncing status (with a rotating aroow) instead of a static one like this one?

[aroby1]

In Edge I see :

In Firefox, I just see:

No blockers active, same computer.  If I look in the developer options on Firefox, there are dozens of 403 errors:

Yet, if I click on one of the URLs, it loads fine.  This is on a brand new document.  I never use the software, just trying to troubleshoot for my wife!

[Imaginerie]

I am also using Firefox for Adobe Express, but used Edge when it was not available on FF prior. The firefox availability is very new, and it's still lacking a couple of features compared to the 3 other compatible ones (and all the alternative browsers that use either FF or Chrome as a base). I will try to find out if it's part of one of the usual bug, and come back if/when I have an answer.

[Imaginerie]

For reference the compatible browsers are : Safari, Firefox, Edge and Chrome.