Hi @Kulbachny89 . This is the reason:
" The spectator mode news was revealed Esaki in the Forza Monthly August 2023 livestream, where he confirmed that several [Forza Motorsport ‘legacy features’ would not be appearing] in the latest game. On the topic of spectate mode in FM 8 specifically, Esaki said: “Having players come into a featured multiplayer event and taking player slots, and then spectating? It’s not really the racing [Turn 10] had intended".
Based on this, my guess is that if for example, 5 spectators are watching the race, then only 19 player can drive in a lobby instead of having a full 24 grid.
Please vote here: