I am now starting to experience a similar problem to that Tre4b reported a few months ago which wasn't resolved at the time.
I can send an appointment or a task from Outlook to a map but when I try to sync it I get the "Mindjet MindManager can't synchronize the selected item because it is connected to a different Outlook account" message, which is pretty strange as I'm sending it from the default calendar or to-do list.
With appointments the Outlook link icon is also shown as broken, yet I can open an appointment in Outlook, edit and save it there and the change will appear on the map. Even just the act of opening the appointment in Outlook seems to restore the Outlook linked status, but the sync problem is still there.
The problem with tasks is similar, except that when I open the task in Outlook and edit it, the changes aren't reflected in the map.
Every now and then an Outlook-created appointment will sync OK, but only say 1 in 10 times (with tasks it always seems to fail). If however the item goes the other way, ie, the appointment or task was created in a map and sent to Outlook, then syncing works much more reliably but will still fail every now and then. Edits to the appointment or task will also show in the map more consistently.
I'm using MM version 17.1.167 32-bit with Outlook 16 32-bit (the rest of Office is 64-bit but seems to work OK with MM) and I've never encountered anything like this before.