I have the same issue as Jmabel, but I am able to seemingly always add a note with another account, which I primarily use to add a note with the image annotator on commons.

I for example can see the button add a note at File:PA Cot-Mireille-1882-Frame.png but I can't see it in File:Thun and surroundings from Niesen on 10 September 2023.jpg.

An example from me: I can see the button and notes at https://commons.wikimedia.org/wiki/File:Vegetation_at_Honningsvag_September_2016.jpg but not at https://commons.wikimedia.org/wiki/File:SR_Technics_hangar_at_Zurich_International_Airport.jpg although an image note exists there (both the button as well as the note are not displayed).

Here I found an edit by someone with the same issue who provided quite a lot of details of their user profile in the aim of finding a solution. Tools or gadgets they had activated, browser they used etc. are mentioned. The user doesn't seem to be active anymore, though.

I have noticed that in some files such as this one the Image annotator works with the Vector 2010 (Legacy) but not with the Vector 2022. But also in the Vector 2010 (legacy) the image annotator still only works with the described work-around in the pop-up window. ~~~~

Ok, now the image annotator also only works with a work around with the other account which is this one

For some days in the end of January until the 6 February, the Image Annotator worked with the workaround from the Paradise Chronicle account but with my other account it worked only with the workaround. From the 6 February it switched back, and now the image annotator works normal again with the other account but it doesn't work anymore (or only selectively, have yet to find out) at the Paradise Chronicle account.