All Profiles have the same access (Likes, Playlists, Playcounts, History, Bookmarks etc.). I remember there were Options to share Tags, Playlists with other Profiles, but now it seem to dissapeeared and when switching to another Profile, the Likes and other Personal-Data is the same. (Early-Access, 2.0 1438, Linux 4.4.302+)
Thanks for reaching out. I tried to reproduce the issue you described on my end, but I am unable to do so, I have separate history/playcounts per profile. Is the issue the same if you try to reboot your Roon Server? Can you share a few screenshots showing what you see on your end?