I am on 10.42.7
I don't have the "inside note body template button".
I can not add the template of my own to Suggested Templates in the note body. When I open it it just offers your suggested templates and there are only 10 of them.
When I do save my template and try to load it from the gallery, it tells me new note was created from template, but it has not been. Not a new note, nor did my template load into the note I am trying to create.
Technically almost nothing template related is working for me. I do have the paid account.