Odd Firefox Behavior on Duo V1

Apologies in advance for the length of this post and numerous screenshots.

My Ready Nas is a Duo V1. See pics below.  I'm using FF 142.0.1 (but this issue has been going on for a while now.  My Duo has the "fix" for the cipher error.

My Duo only serves to backup my primary NAS (another brand).  It's on a schedule, so it turns on, backups up a bunch of stuff, then shuts down until the next event.

While it's backing up, I use FF, to view progress, review the logs to make sure to see what has changed.  Sometimes, make an adjustment.  It's been setup like this for quite a while and has always worked fine.  

Until it didn't.  This too happened a while ago and I attributed it to something in FF that would go away after a few more updates.  I was wrong.  So here's what's happening.

Launch FF and go to my Duo login page, login and all looks OK.  Expand the nav bar to access Backup, select Backup Jobs.  The menu will collapse (not go into Backups) and the Home banner will have an extra Duo (ReadyNAS Duo Duo).  If I repeat the same steps, same result but I'll have 2 extra Duo's (ReadyNAS Duo Duo Duo).  Yet, If I select Time Machine instead, Time Machine page will open OK.  If I use the tabs to go to Backup Jobs, then Backup Jobs open OK.  I can then view logs etc.

This behavior is not limited to Backup.  Generally any of the main sections, like Network behave in similar fashion.  If I select Network Interfaces, I get another Duo.  If I select Global Settings, it opens OK and I can select Interfaces from the Tab and get in OK.  

Same thing applies to all of the other main sections.  Some will close and add a Duo, some will open OK and I can use a tab to navigate back over

Now, I launched FF in "troubleshoot mode", reset FF, and even uninstalled FF, cleaned up all the leftovers and did a fresh install with no modes (not even the TLS setting), Same result.

So, while a bit aggravating, the cipher fix does allow me to use my other browsers instead.  I can use Brave, Chrome, Opera, even Edge (all Chromium) so this issue is not that critical and I've simply  used one of them instead of FF.

However, my curiosity has gotten the better of me to try to understand why?  SO a bunch of screen shots follow.  If you've run into this before or have other suggestions, let me know.  Looks like I can only add 1 attachment at a a time.

Screen when I login.