Paul. I'm using Firefox, also. My experience is that 'refreshing' Firefox usually resolves problems of different sorts that I have experienced. While there are problems you have described that I believe are settings that can be changed individually, 'refreshing' Firefox resets everything to the 'common' setting that user usually use or are Mozilla recommended.
I don't want to mess you up, but consider trying the steps I've listed below.
Reference the rectangle in the upper right corner of your Firefox web page. Click on the rectangle and go down to the question mark next to the word 'Help' next to the bottom of the list . . .
Click on the Help listing . . .
On the page that opens, click on 'Firefox Help' . . .
On the page that opens, go down to the exclamation mark on the 3rd row down that reads 'Fix Slowness, Crashing, & Error Messages, and Other Problems'. Click on it.
On the next page that opens, go down to the 9th title that reads, 'Refresh Firefox'. Click that title and you're on the path to refresh Firefox.
Refreshing Firefox should get you squared away.
Hope this helps!
NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York