hi,
1.just to be clear, the distribution group is working fine for on-premises users and for cloud users who are migrated, so when we sent an emails to the group, o-p users get it, migrated user also get it, user created from AD and sync to cloud don't get it, it occur whenever local or O365 user send to it.
2. i can check it on the local, i dont have list on cloud
3. yes it can
thank you