If you have the time (!), there’s a whole thread devoted to discussing the philosophy of whether 100% means open or closed as far as a cover is concerned.
But the thread does also contain a workaround solution from community member Petro which involves setting up a template cover, and hiding the original entity (per dbrunt).
Quite a few of us seem to use a template cover as a way to get around this issue of having the buttons the wrong way round in the HA frontend - with a template cover, you can flip the open/close operations if you need to (which is not done in Petro’s example linked above).