I have two phones, an S7 and an S9.
On the S7 the Samsung Calendar App can access Tasks and Calendar Events on my outlook.com account, with full read and write access.
However on the S9 the Samsung Calendar App can access Tasks on outlook.com with full read and write access, but it can only access Calendar Events in Read Only mode.
The settings on the S7 and S9 phones are exactly the same, so I think there is a bug in the Samsung Calendar App on the S9.
Could you check that both the apps are completely up to date for us please?
Yes they are both the same version 4.4.02.102 so it’s odd that it works on the S7 but not on the S9..