Which connector?:

Amazon Ads connector

Additional details:

Please see the following findings from Fivetran support. We've been advised an internal ticket was created. We wanted to created an externally accessible feature request. 

Based on our analysis and the information shared by Amazon, the behaviour you are seeing appears to be related to how the Amazon DSP APIs return accounts for this specific setup.
 
Currently, we use the Profiles API to return the profiles in the UI, and manager-level accounts are not supported at this time. Amazon Ads Advanced Tools Center.
 
Our review suggests that supporting this scenario would likely require a connector enhancement to use an alternate account discovery approach for linked advertisers. This does not appear to be a configuration issue on your side.
 
I have opened an internal feature request for further enhancement. Please note that we do not have an ETA for feature requests, as they must go through consideration, feasibility review, approval, and prioritisation before implementation.

Support link: https://support.fivetran.com/hc/en-us/requests/388796