Hey Chris, thank you for your reply
The ADLS is in the same region as the data verse.
I have removed the 'private endpoint' from ADLS to see if that made any difference and it didn't.
Next I looked at the 'network' configuration for the ADLS and it seems that when you change it from 'all networks' to 'selected networks' even with the 'Allow trusted Microsoft services to access this storage account' option enabled it stops the data verse 'export to data lake' from working.
So it looks to me as though we need to configure ADF pipelines to load data into ADLS from the data verse if you want your ADLS secured with no public IP access. Creating an ADF pipeline is a lot more work than using the out of the box 'export to data lake' feature. Or am i missing something?