I can’t ‘remove’ a z-wave device

How confident are you at tinkering? You've got yourself a couple of ghost devices. I had a similar problem recently where the native remove option wouldn't remove a ghost. Luckily @danabw has written an excellent guide on how to use a UZB (or other Zwave stick) and SiLabs Zwave PC Controller to remove them. You can find it Here. In that post, he has a link to a PDF version of the process. i highly recommend downloading it and keeping it handy or even printing a hard copy for reference, I will add (and this won't make sense until you try it ) If you have a C8 hub, Smart Learn mode didn't work, I had to use Classic and remove it. But either way, it usually works really well.

You can pick up a UZB7 from Digikey for around $20. It's a handy tool to have around. I recently tried a Zooz 800 stick but did not have much luck with it.