Previously opened tabs don't have URL when I come back at a later time

Hi,

I've been noticing this for many months or maybe even a year. I'll have a dozen or so tabs open that haven't been looked at for a day or two, to many weeks and when I go back to look at them the url is empty but part of the name of the website is in the tab. Reloading doesn't work, going back doesn't work. I am unable to load the website when this happens and essentially lose that information on the page. This happens on firefox ios Phone, iPad, Windows 10 and Mac. All devices have a lot of space on them but the phone only has 12gigs available. It seems like its happening more and more. I don't have any add on's. I also see a lot of tabs open that has "about" in the URL, I don't know why this is and or maybe its related.

Thanks for any help. Greg