I think I found a bug. I had added multiple fields and templates to Basic (and Reversed) which created 12 cards for each note. 4 copies for 3 templates. This was a mistake, I realized that is probably had to do with the and Reversed setting so after messing around for a bit I changed it to Basic reset everything to default settings. but now the notes in this deck have 5 cards being produced from default Basic. All the other decks on Basic are sill fine with 1 card per note. There is only 1 template in Basic. I’ve quadruple checked. It’s not another type with a similar name. This is default Basic, But there are 5 identical cards produced for 1 note.
Found out if I copy the note, the card count goes back down to 1 for the copy.
Have you tried running Tools > Empty Cards and/or Tools > Check Database?