@Tessa295 Hello! To sort the immediate issue the other owners could just go here for the pending approvals Accept or deny requests to join a team - Office Support (microsoft.com)


As for why the other owners don't receive the emails makes me wonder if it has something to do with being a "subscriber" for the group or not. Not sure to be honest. Try using the Get-UnifiedGroupLinks to see if there are any differences when it comes to the subscriber settings for the owners in this particular team. If so you can use the Add-UnifiedGroupLinks.


Get-UnifiedGroupLinks (ExchangePowerShell) | Microsoft Docs

Add-UnifiedGroupLinks (ExchangePowerShell) | Microsoft Docs


There's also Set-UnifiedGroup (ExchangePowerShell) | Microsoft Docs which controls many other settings and more specific -AlwaysSubscribeMembersToCalendarEvents and -AutoSubscribeNewMembers


Depending on your current settings perhaps a removal (wait a bit) and re-adding of the owners to the team (group) will do the trick as well.