D365 App fro phones connect D365 v.91

When using the D365 phone app on my phone the default view for related activities always appear to be a calendar control instead of a read only sub grid. The default out of the box is a read only grid so I am confused to why I see a calendar instead. I can switch to the sub grid but why will it not display the sub grid as default. Has anyone see this issue before?

It appears to work ok on the tablet app.

Thanks G