This content cannot be played on this device - apple TV4k using home sharing from mac OS Catalina [purchased content only]

I've been running an "itunes media server" for a while now, having all my content on my mac and allowing my Apple TV devices to play content from it.

It has worked perfectly for multiple years which justified the investment in the apple echo system.

My Mac OS host that serves the media has been upgraded to Mac OS Catalina (currently at 10.15.1 at time of writing).

The removal of i-tunes and replacement of apple TV app and moving the home sharing functionality to the "sharing" section of the Mac OS component caused a minor re-education and setup.

My Mac currently has "media sharing" enabled and "home sharing" enabled under that, and my apple TV device can browse the media library for music/TV/music shows, works exactly as expected until I tried to play a TV/film file that had been purchased with itunes and downloaded onto my mac.

If I play a video file that I've imported myself eg: DVD rip, home movie etc, the apple TV device can play it fine over home sharing, if I try to play a video file that I've downloaded as a result of purchasing from apple's itunes store I get the error "This content cannot be played on this device"

This has never been a problem before the upgrade and I was able to serve my legitimate purcahsed apple content from my mac to my apple TV via home sharing, I can no longer do this.

My debugging to date has included disabling and re-enabling home sharing on the mac, signing out/in to my home sharing account on the apple TV, deleting the purchased content from the mac and re-downloading it using the TV app, and the obvious restarting my mac and apple TV devices.

None of this has worked and my apple TV is now actually mostly useless as I'm unable to play on my TV the content I've purchased on my mac.

Is there anything I've missed to enable this with Catalina ? as the media is browseable, and the non-purchased media is fine, it's just legit apple purchases that don't work.

thanks.