Can't play multiplayer on Xbox Game Pass PC

Are you on PC or Xbox? What games are you trying to play online multiplayer on? Don't forget, you have to have a subscription to play online multiplayer on Xbox. Game Pass Core or Game Pass Ultimate will give you access to online multiplayer on Xbox.

Thanks for the reply. so if I switch from Xbox Game Pass Ultimate to Xbox Game Pass for PC (Beta) which costs less and is oriented only to PC players, if I install a game from the catalog and this game also has multiplayer I cannot play multiplayer with
the only Xbox Game Pass for PC (Beta) ? it seems absurd ..... -.-"

There Game Pass for console, which is for the Xbox One and Series S/X and then there's Game Pass for PC which is only for PC. They each have a lot of the same games, just console vs. PC, and PC Game Pass does have less games than console. If you would like to play games on both the console and PC, then you would want to look into Game Pass Ultimate which includes Game Pass for console, PC Game Pass, and Gold (which would need to play online multiplayer on the console anyway).

Sharing through Xbox is not done the same way a Nintendo Online subscription is done. You can't actually share the subscription, but you can set a console as your Home console and other people who use the console would then be able to access online multiplayer (if you have Gold/Ultimate) and any games you've downloaded from Game Pass or purchased.

Have you tried playing online multiplayer in a game yet? Game Pass Ultimate includes Game Pass Core (Gold), Xbox Game Pass, PC Game Pass, EA Play & Cloud Gaming.

The difference between Gold an Game Pass Ultimate is that Gold is just for playing Multiplayer. Ultimate has included the Game Pass for Xbox and PC.