The situation takes place in an online Pathfinder 2 community. Here everybody have PCs and can play on any session with a level that more or less matches the level of one of his PCs. A handful of those persons are also GMs and organize the sessions (by vocal+a VTT). There are guidelines about many aspects of the games (like the amount of xp per session so that each encounter is worth a certain amount of xp depending on its difficulty).
The problem I encounter is that when I have the most ancient members of the community as players on my games they tend to behave like they were the gamemaster, and have expectations that the game is ran as they would run it, which can be more or less troublesome. For example:
They ask other player for checks
They correct me by quoting the rules of the book when I want to enforce rule of cool
They look at the monster’s stats to correct me on how they work in the middle of a fight
They are bad sports when I correct them about a rule they got wrong
They grumble about the amount of xp I give to them because they think the combat encounters are worth more
Outside of those games they are nice people, but the more I play with them as players the worse it gets. What can I do? I don’t have any issue with the other players on this community.
There are similarities with this question but as here I am in the GM position and it is an online roleplaying community I think it is worth a different question.