stuck on "checkpoint arrived" with firefox and Ledger Nano S

stuck on "checkpoint arrived" with firefox and Ledger Nano S

Because of the recent issue with the latest Chrome/Brave update (Metamask is broken with last Chrome update), I have to use Firefox.

All was good until I got to this point : Continue

I clicked, and then the Continue button keeps on spinning and it won't go to the Metamask dialog.
Stuck there.
(see attachment)

It seems like the firts part of the TX was completed