Your screenshot looks fine.

If you are running in private browsing mode, only extensions that have permission to run in private windows will appear in the panel.

Are you kidding me right now? Most of my add-ons are not on the list, and there is no way to scroll down, so I can't add them to the toolbar or take them off of the toolbar. I'm not in private mode. Now NONE of my add-ons are showing on the puzzle piece, and only a couple are showing on the overflow because I dragged them into the overflow on customization, but there are some that I can't drag to overflow, because I can't get them onto the toolbar, because THE PUZZLE PIECE DOESN'T WORK!!

This has been a problem for YEARS with Firefox, if I'm reading past posts correctly. It was working fine before the last update, and having updates break things while Mozilla denies it is historic! I've been using FF since V.1.0 and I'm telling you, I'm sick to effing death of the lies and denials.

I'm going to try to go back to a previous version to see if I can get things to work again. I've already had to create a new profile to get scaling to work correctly on some pages, including YouTube. I'm ready to leave FF YET AGAIN, as I have many times before, until they stop denying that they break something with every update, or the stop taking away perfectly working and useful things. No wonder Chrome is kicking their ass.

Private browsing mode (aka "Never Remember History") has no visual indicators, so you could be in that mode without knowing it. Try giving extensions permission to run in private windows and see if they show up.

only a couple are showing on the overflow because I dragged them into the overflow on customization

You can't drag extension toolbar buttons into the Overflow Menu anymore, they are either in the Extensions panel or pinned in the toolbar.

What version are you talking about, because I'm on 121.0.1 and it says it's up to date.

I repeat, I KNOW what private mode is, and I am not in private mode. In fact, this is a brand new profile that I created to try to solve the problem with the puzzle piece and a problem with scaling on some sites. I haven't changed any settings on it at all, so everything is default. Unless private mode is default, I'm not in private mode, and my history is showing. I'm not in a private window, but it doesn't matter because all of my add-ons are allowed in private windows. So I don't understand what you're saying about private mode.

As far as dragging things into overflow, you're telling me I can't do something I JUST DID. If you go into "Customize Toolbar", there is a cloud that allows you to drag any add-on that is on the toolbar into overflow.

The strange thing is that some add-ons will not show on the puzzle piece, then later they will show, but greyed out so I can't add them to the toolbar and drag them to overflow. The two that are like that now are "Don't track me, Google" and "Reddit Enhancement Suite." Can you tell me why they are greyed out, because they have never been greyed out before.

You know what, I'm just going to downgrade to the version before this last upgrade so things will work the way they are supposed to, and wait for FF to fix this stuff. The only reason I don't like Chrome is because UBlock origin doesn't work on it, and there is no decent ad-blocker on it that works with all my sites. Otherwise, I'd be using Chrome now.

Grayed out extensions do not have a toolbar button, clicking on them does not open a panel or perform an action, so you cannot pin them to the toolbar. Older versions of Firefox are the same, extensions without a browser_action like "Reddit Enhancement Suite" and "Don't Track Me Google" do not appear in the toolbar.

Dragging extensions into the "Overflow Menu" section of Customize Mode should not be possible in version 121. Does it still happen in a new profile? An easy way to test a new profile is to install Developer Edition and see if it happens there or refresh your existing profile. Make sure you stay signed out of your sync account when testing.

OK, I have been playing with it, and somehow, it's working now. The only thing I had a problem with was removing some that automatically added themselves to the toolbar when I re-enabled them.

Thanks for your help.