We have discovered some changes in how data is being passed from Salesforce to HubSpot (API) and how notifications are being triggered and other implications to data passing between systems. This appears to have happened over the last week and you may be getting emails from your Sales team to turn them off.
Are you seeing similar issues?
We have a few solutions to at least stop the immediate impact but want to understand if this is just us or if you are seeing this as well.
I had a look around in Community and couldn't find a similar issue being raised.
I would recommend connecting with HubSpot Technical Support, as Support is included in your subscription and they will be able to provide real-time assistance for this matter, where you are able to share screenshots and examples about this.