Trouble with still images imported from Premiere.

Trouble with still images imported from Premiere.
I've imported a project from Premiere from an XML that had several .tif and .jpg with moves on them. The moves didn't transfer across from Premiere, but ok.
I then rebuilt them in Resolve in Edit using the Transform >zoom. They work fine in Edit, Color and Delivery. Then I exported / rendered them in Delivery as individual files along with the rest of the project using the Premiere template. Brought the XML back into Premiere, everything is there except no motion on the stills images. I upgraded to version 17, retried it, same result, no moves, and stuck with the wrong sizes to copy the attributes from the Premiere clips.
I did find that I could render the stills as "single clips" and the motion appears on the clip, then manually reedit them in. I've got to be missing something here. Doesnt it bake in the images moves when it renders? Is there something about the tif and jpg images that it renders them differently? Big workflow issue. What am I missing??
Thxs Jon
I'm in Mac Mojave, Premiere 2020, iMAcPro. DaVinci Resolve 17

What you are missing is that the Individual Clips render option is for round-trip workflows only. When doing a round trip from Premiere, do the moves on your stills in Premiere, do the colour grade in Resolve and when you re-import the new XML from Resolve the moves will be preserved in the new timeline. Always follow the correct workflow for a proper round trip from Premiere to Resolve and back again. Render all clips at source resolution for a proper round-trip. Also the two clip scaling options in Premiere Set to Frame Size and Scale to Frame Size behave differently in Resolve, as one option will scale the clip to the timeline resolution in Premiere but keep the metadata for scale at 100%. This upsets all scaling from Premiere to Resolve.

Thanks much for your reply, makes sense. Will try that out.
Thxs Jon

Thanks, so working on it. I'm not seeing the sizing info coming back into Premiere. What settings work best going out of Premiere, then which one to use coming back in. Scale or set? Is Resolve removing them somewhere?
Also I'm using the Premiere XML setting leaving Resolve, are there settings within that would affect it?
Is there a good run down on this part of there round trip, been looking and looking for one.
Thanks!!
Jon