HS - BG - Duos - Unit deleted after combat

Played a baron on my board, I couldn’t move it around but I could move other units to behind it/in front of it. End of combat (Team mate solos both boards) the baron shows up to count for damage (It was not my first unit on my board and was the only unit of mine to show up), start of tavern round I only have 6 minions and I can still play units.
AFK + Chen hero combo.