Publish to web - checking limitations

Hi folks

I have a data model in Power Bi desktop which i have used to create Reports that i have successfully published to the web, using the embed code. A few additional queries and pages later and that function no longer works (and the Publish to web option is no longer available within the Report). I am guessing that i have hit one of the known limitations (unknowingly) so my question is:

what is the best way to check what the problem limitation is?

I have already:

- cut down the Report into smaller component parts and re-tested (the newest additional queries work on their own, but the original, smaller report with the original queries still does not work!)

- i have removed the new trial R visuals

- i don't believe i have RLS set up (no users, permissions etc)

- queries are links to Excel tables, or Power Query code (both of which worked originally)

Not sure what else i can check, or if any of the above may still be inadvertently causing a problem?

Any help very much appreciated.

Thanks

Chris