When a new update releases, it is rolled out gradually across different platforms. Because of the temporary game version disparity between players you may experience overly long matchmaking times, and inviting another player to a squad may trigger an error.

How matchmaking and squads work during updates:

• You can only form squads and play with players who are on the exact same game version as you.
• As each platform receives the update, updated players are grouped together, while players on older versions remain in their own separate matchmaking pool.

If you can’t invite a friend to a squad, it simply means one of you has already updated and the other hasn't yet.