Sending conversions to Google Adwords through Marketo launch point

Hi, we are using an MCC account in Google Ads, a parent account and some different children accounts. When integrating Marketo and Google Ads it only integrates with one of the children accounts and not all of them. According to the documentation Marketo should show a screen in which it shows the different Google Ads accounts we can sync but for some reason Marketo does not display that screen. We reached out to Marketo support and Google Ads support. Each blame the other one and we don't have any answers. 

Did anyone encounter a situation like that before? Any idea what can we do?