I'm sure there are quite a few people that are having this issue. Upon spawning certain Pokemon, their HP (Not the MAX value) will change. I have a Deerling here that's considered to be one of my favorites, but whenever I spawn her from her Pokeball, their HP snaps from FULL to something lower. How much HP is lost due to this bug fluctuates. I believe not ALL pokemon have this problem (e.g. Arceus). But this issue is rather unsettling and brims down the use of healing your Pokemon. I've made sure it was the mod itself and nothing else by testing the mod without other ones in play simultaneously.
I hope this gets fixed soon.
P.S. I submitted a support ticket on this issue, then I replied to it, updating my findings because the HP can change back up too if the HP is NOT FULL. I don't know if it affected the priority of the ticket but this led me to create an account so that I could submit a ticket from an "official" account instead of a guest one, but for some odd reason, it is not letting me log in via the Support tab (Man, nothing's going my way nowadays, huh).