Hi @rulpats. In my experience with HubSpot, “Opportunity Stage” is not its own standard HubSpot property. It is, however, a stage in the HubSpot lifecycle stages property.
If it’s a separate property in your HubSpot instance, I’d look into who crated and ask why.
If it’s part of the lifecycle stage property, that’s the property (or field) you’d want to look into. That could be what’s driving the update in SFDC.
Hope that helps clear it up!