To Do not syncing with Tasks by Planner and To Do in Teams

I create Tasks by flagging email in outlook. They then appear on my Task list (Outlook/Teams/iPhone App). When I add them to "My Day" on the iPhone App they don't sync and appear in the "My Day" in "Tasks by Planner and To Do" in teams.

They do appear in To Do in Outlook on the laptop. But To Do in Outlook on the laptop local installation keeps cracking and freezing so I can't scroll down the list of Tasks to see them all. When I try to scroll To Do restarts itself.