Typing autocomplete seems to be non-functional after update?

I'm thinking of two different features that could be relevant here:

(1) Autofill visited site URL

When you type one or more consecutive letters into the address bar, Firefox will often display an address of a previously visited site inside the address bar based on some mysterious combination of the frequency of your visits to the site, recency of visits, and alphabetical order. Once the right site is filled, you can visit by pressing Enter (no need to select from the drop-down).

(People find this feature confusing because they often are thinking of the title of a page, like GMail, rather than the url, which starts with mail.)

From your first description, this has stopped working for Twitter. I wonder whether this is related to Twitter URLs redirecting to X (if the redirect lowers the ranking of Twitter URLs so they aren't used for autofill??). Is Autofill working for other domains?

(2) Bookmark keywords

If you right-click your Twitch bookmark and choose Edit Bookmark, you should get a four-line dialog where the fourth input is "Keyword". If you enter tw here, then when you type tw in the address bar, the top row should show that Firefox will visit your bookmarked URL if you press Enter right now (no need to select from the drop-down).

That might be a useful workaround for cases like this one.

For #1, autofill doesn't seem to be working at all besides just the search suggestions as mentioned. Like it won't give me any actual URLs like it previously would. As another example I have Google Photos as a bookmark, and its url starts with "photos" besides the https:// but if I start to type "photos" it doesn't show up at all. It only shows one of my own searches using the phrase photos in it, and then the suggested searches of other words in general using the word photo.

For #2, that workaround does work if I want to go that route at least so that's nice, until I figure out why it isn't working normally. So thank you for that.

The only reason I can think of that in-URL-bar-autofill would stop working is if the scores for all the sites reset to zero somehow. Or if there is some kind of data corruption in the Places database where that data is stored (along with bookmarks and history).

Could you see whether there are any relevant messages in the Browser Console? You can pop that window open using Ctrl+Shift+J. Position/resize the window alongside your test window so you can watch for messages as you type in the address bar. Meanwhile, the console may flood with messages from other functions. Click the trash can to clear it. Then try typing a letter in the address bar, wait briefly, add another, wait briefly, etc. Does the console show any errors (pink background) as you're doing that?

Strangely it seems to have fixed itself?

The other thing that was broken were the bookmark icons which was suspicious as well and maybe a related problem. But they seem to be randomly working or not. I even tried to use an extension to refresh every single bookmark and somehow they are still partially broken but I guess that's a separate issue now anyway.

I went to try and do what you said and when I first did that shortcut there were some errors but I didn't know what they meant so I did the trashcan to get rid of them as you mentioned. But I thought since I used that workaround I should remove that first on the bookmark itself before testing it, and I DID have that set to "t" for my Twitter/X bookmark but for some reason when I went to remove it it was already gone...

Then I tried to test typing other stuff and everything seemed to be working like normal again. I do not know what caused it or what actually "fixed" it.

I'm not sure if I should mark the other post as the "solution" or not since it was a workaround that worked but not exactly solving the initial problem since it randomly decided to work again.

Hmm, I'm not sure what happened. Maybe there was a transitory period where Firefox couldn't read the database normally (for example, if another program locked the file for some reason) and then Firefox regained access and discarded changes made during that transitory period. Or I guess that's just another guess and it could be sh*t happens.