Hello @TDorge
I just tried it myself - placed the path to a Word template (dotx) file in a variable. Added it to the Populate a Word template ... and it did not recognize the content containers in the document - gave me the dynamicFileSchema instead, which apparently noone knows about 😄
Renamed the Word template to docx, so it was still a template inside, added it to the step by navigating to the file. Now shows my two content containers - added the image object and ran the flow. Word file created, but failed to open in Word.
Renamed the Word file to dotx, open in Word, saw my image, but only in the body, not in the header.
Suggest you to post this as in the idea forum!
Kind regards, John