Hi everyone,
Right now, I’m working with a vendor to help ensure Salesforce and HubSpot are syncing appropriately with each other. We’re updating some of our forms to include some new contact fields, and testing them out to see how they sync to Salesforce.
Recently, I encountered an issue where I submitted a test once, everything worked fine and synced to Salesforce appropriately as a new contact, and then I tried to submit through the form again pretending to be a different contact to do a secondary test. For some reason, every time I try and submit to the form again, it will not sync to Salesforce at all.
No contact record created in Salesforce from the submitted info, no updated contacts, nothing. Only thing I see is through HubSpot, a record was created from HubSpot, but was not assigned a contact owner like usual. It worked once, and now it no longer does.
I had a colleague attempt the same thing, and it worked for them just fine. Is this an IP issue, is HubSpot blocking anything? I’m happy to provide more information if necessary, but I’m wondering if this is some sort of IP block since I performed these submissions from the same device at the same location.
Thank you in advance for the help.
Hey, @DLalonde 
I don’t know the exact cause here, but testing forms can be tricky. I’d try:
- using an incognito tab
- create a new form to test with and make sure this setting is enabled: “Automatically create new contacts from unknown email addresses:”
- try submitting the form after clearing the cache and cookies
Because it worked once for you and for your co-worker on the first try, my gut says this is a cache and cookies issue. I’d start there before trying more complex troubleshooting. — Jaycee
Hi @DLalonde
What you’re describing usually happens when HubSpot thinks the second form submit belongs to the same visitor not a new contact.
The tracking cookie (hubspotutk) and browser session override whatever email you type, and HubSpot routes the submission to the existing record instead of creating a new one. That’s why you saw: A HubSpot contact created, No owner assignment, No Salesforce sync, and no duplicate created on the Salesforce side.
HubSpot documents exactly this behavior: form submissions always bind to the tracked visitor first, not the typed-in email, so testing multiple “new” contacts from the same machine produces misleading results (Track visitors in HubSpot )
Clearing cookies or using incognito will let you reproduce the original behavior.
The other factor that blocks the Salesforce sync is that the Salesforce connector only pushes when HubSpot thinks the record is new or meaningfully updated, and cookie-based merges prevent that. That’s why your colleague’s test worked: different browser, different cookie, clean path.
Since you’re validating a Salesforce–HubSpot sync pattern across multiple fields and form variations, you might consider simplifying the flow entirely. Stacksync cuts out these tracking cookie edge cases because it doesn’t rely on form events to decide what syncs. It keeps HubSpot and Salesforce in continuous two-way alignment every field, every change, instantly so you don’t hit tests that “work once, then break” depending on browser state. Hope this helps.