We have a connection to our ActiveCampaign account which works well for synchronizing Contacts and ContactCustomFields to MySQL; but when using the same connections to synchronize ContactCustomFieldValues, the integration simply hangs.

There are no errors, but the integration has currently been in the "Running" state for ~46 hours (from 2023-05-10T18:30 UTC to 2023-05-12T16:00 UTC) and shows 0 rows synchronized.

Noting for background that our ActiveCampaign account has about 127,000 active Contacts, and 68 ContactCustomFields