Only able to add some teams to a calendar invite & not all teams populate

[JGarc2020]

Hello! Need some guidance here. When creating a meeting  I am only able to add certain teams & not all of them populate so they can be added to the invite. Anyone know why? 

Thank you,

Judy :)

[#2]

when creating a team/group, there's an option to make it publicly visible in Active Directory. Maybe that's why? Some of the teams are not public.