Something interesting I just noticed.
This is now what the Next blue LingQ shortcut looks like for me on Firefox:
Note: Before the latest update, this shortcut on the Firefox extension appeared like in the below image (i.e. b for next blue Lingq), and I was having more problems getting the shortcut to work.
This is what it looks like on Chrome:
[Stay with me on this.]
When I rebind the shortcut on Firefox to be the same as the Chrome image (initially how LingQ intended it), the shortcut doesn’t work in Firefox.
But if I set the Firefox extension to the shortcut shown in the Firefox image and use " b " as the shortcut (not Shift + B), the shortcut goes to the next blue LingQ as I want to. (Note: my caps lock is not on at any point). And Shift + B doesn’t seem to work.*
*This is also applicable to the Chrome extension.
Does any of this help or make sense? Anyway, I’m going to test this out for a while and see if this fixes the issue for me and allows me to avoid going through the process I detailed in one of my edits here.
P.S. Though all of this could be a weird coincidence that doesn’t help at all, 
