Function isn't relyable shortly after login Edit

The Problem Edit

If this function is used shortly after login, it will return nil although you are in a guild.
Even after both events ADDON_LOADED and VARIABLES_LOADED are fired, the function is not relyable yet.

Any known solution / workaround? Edit

I thought about using the GUILD_MOTD event for notifying me about being in a guild (even GUILD_MOTD is fired before IsInGuild works correctly).

Maybe this is already a known issue Edit

Add a link to related articles if that is in case (API IsInGuild, API GetGuildInfo, ...).