Or is this normal since I only have that one imported in Kleopatra?
It looks normal to me and this seems to be exactly your case.
I didn't see that for very long since I do have all signatures imported and, if you want more peace of mind, you can do the same, since it's not a big deal.
You can download the others' signatures from either the Electrum download page.
For example you Right Click on SomberNight, save as.. and get the file (make sure it's saved as .asc and not .txt). Double click it, you have to press next and check a couple of checkboxes here and there and you're good.
Then (when all 3 are in order), if you verify Electrum again, it will be all nice and green.