The problem is inconsistency. I’ve come across many releases marked as a single on Spotify and Deezer and then an EP on Apple Music or vice versa. There are also cases of EPs marked as an album. Happens a lot in k-pop where mini albums (which are literally just a marketing name for EP) are credited as full albums on these platforms.
There’s also another issue. Spotify tends to group previously released singles from the same album together whenever the artist releases a new one. Usually if it has like 4 or 5 singles, it will be marked as an EP, but on Deezer and sometimes Apple Music (if there’s no pre-order for the album yet), those are usually realeased as 1-track single.