Helga,
I have good news: it’s working and I figured out what was causing the problem.
So I am creating my custom taxonomies using the Types plugin, and when doing so there are various settings that I can check/uncheck. One of them is to ‘show admin column’, and it was not checked, and this was causing the problem.
See screenshot here: https://imgur.com/C0pzmc4
The reason I didn’t notice this before is because when I would click the ‘quick edit’ option on my post listings, it would expanded to show my taxonomies, and from there it would seem that I could edit and save them (which did not work, as you know). However, now that I have checked the checkbox to ‘show admin column’ , the taxonomies show and i can indeed change and save them from right there in quick edit.
Up until today, I didn’t notice that this particular taxonomy didn’t have it’s own column in the post listing, and i think this is why i was so confused when you wanted me to show you the html for the taxonomy column on the edit page—because there was none! Today I realized I wanted that taxonomy to show like the others with their own column, and hence my discovery.
I’m sure it might still be confusing for people like me who don’t want a column for the taxonomy showing on the edit screen, but so far as i’m concerned i’m very happy that it’s now working as I had hoped.
Thanks so much for all your time and effort for this plugin and the support here . I know we are all so busy and us users are so constantly in need, it’s not easy! ?? ??