Thanks for the tag @Jaycee_Lewis. Unfortunately @LisaMaudrich I don’t have experience with this issue. Here’s what I’d do if I were in your shoes.
Since the contact exists in AC but isn’t updating, is it an issue on the AC side for importing historical data? I’d check my AC settings on this one.
I’d check the HubSpot settings as well to see if it’s set to only push new contacts. In the Salesforce integration, there’s an option to keep SFDC as the source and only push new, so I wonder if it’s the same for ActiveCampaign.
Have you checked in with HubSpot Support?
That would be my order of operations here, were it me. I hope that helps.