Hi
After some experimenting and testing, I found a workaround which means rebuilding the reports rather than a simple export as before. Possibly this is related to network security and/or the Outlook Client being replaced with a different sort of application.
You'll need a username/password from a Dynamics 365 user to have Excel load the data regularly to the PC that is feeding those monitors.
From Excel, open the 'Data tab', open 'New Query', choose 'From other source', 'from Dynamics 365 Online'. Excel will need a "Web API URL", which you get from the Dynamics 365 'Settings/Customisations/Developer Resources' screen.
Now what follows is that you need to build your reports in Excel. The window that pops up lets you pick the entities in Dynamics where you will get data. The Edit button lets you make filtering and pre-processing before the data goes into Excel.
This is essentially the same process you'd follow to build the report in Power BI, so we're talking about creating new columns, replacing GUIDs and data values with data labels, etc. You might do a lot better by picking a Power BI template or report set and build your status screens from there!
When you are ready, use the "Load TO" button rather than "Close and Load". This will give you the option to load the data to the Excel data model rather than dump data into a table. This makes it easier to build and format your reports using the Pivot Table and Pivot Chart tools.
When done with the formatting, the Data tab will have a 'Refresh all' button, which you can expand to access 'Connection properties'. This is where you set the refresh interval. Save the file and you're done.
I tested this only very briefly and I find it works but is too complicated. Sharing the completed file requires the end user to authenticate in Excel with a Dynamics user/pwd.
Next, I'll try to do the same with Excel templates in Dynamics 365, I think it might be a better way forward.