Back button on all remotes stopped working only in Emby

[Gilgamesh_48 1240]

Last night my Roku Ultra had its back button stop working but only in Emby. In all other apps and in the Roku interface itself the back button worked fine. I first tried exiting the app and then reentering and no difference. Then I tried a simple reboot and the symptom was unchanged. I then tried a full power cycle and no change  I Then checked for updates and thee were none available for either the Roku or any app. I know I should have done that first but it was very late *early* so I did not think logically. I tried the voice remote and an ir remote and a universal remote and the back button did not work on any remote but all other buttons worked fine on all remotes even the Roku app on my phone and the back button there did not work in Emby but worked everywhere else I tested. 

I then gave up and switched to my Fire stick for the remainder of the evening.

When I woke up this morning I checked and the back button was again functional and everything seems fine. 

When I had the problem I tested both my Rokus and all the remotes that are attached to them and the back button was dysfunctional on all of them but only in Emby. This AM everything was fine on all my Rokus.  

I have no idea what happened but it was rather disconcerting and I have absolutely no idea why it only happened in the Emby app but it did. 

This report is just for info as everything is working fine now. 
Of course any guesses as to what happened will be met with gratitude and might lead to an idea if this happens again. 
I just do not understand how all my remotes on two different Roku Ultras can suddenly have the back button stop working only in Emby and then, several hours later, start working again.

To be honest I would attribute this to my old age or some other mental factor but I do not think my mind can fail in such a very specific manner. 

Sorry for rambling a bit but the nature of this problem is such that it has me rather befuddled.

I do not expect a "fix" as nothing is actually broken at this time.  

[Gilgamesh_48 1240]

Apparently I ran into one manifestation of this problem:

Some Roku Users Unable to Use Back Buttons on Remotes

I did not se the problem in all apps so I conclude that the bug shows up differently for different users. But it is good to know that I was:
A. Not imagining what happened
and
B: Not totally insane.

I guess this is a case where I am relieved to not be alone in my misery. 
But I also guess that the case of "B" is not actually proven.