In the poketch app it said my budew had 0 hearts, it was neutral when click and holding the cursor over it and when I held it slightly further away it would run away. Unlike the prinplup and 2 others that would move towards it with 2 hearts.
Budew then proceeded to evolve at level 25 into roselia, which shouldn't be possible at 0 hearts. Apparently 2 hearts are needed to evolve it.
Also, the high friendship messages that appear with the other Pokemon didn't appear with the budew and certainly not with the roselia.
Update: After turning the game off and on, it turns out that the roselia actually has 2 hearts. Seems to be a bug that occurred.
Source: https://www.ign.com/wikis/pokemon-diamond-pearl-platinum-version/How_to_Evolve_Budew