What I think is there will be two possibilities in your case -
There might be an issue of your device and internet connectivity because in my experience I had faced this issue not just for HubSpot but for other apps as well when I am facing connectivity issues or caching issues, I would suggest try it in Private mode on your browser once and yes try on different device or you can even test it once on your phone browser on desptop view.
Second might be you have integrated with some apps or third party tool integration where HubSpot API endpoints might be used so due to which a wrong query been fired or may recurring query is been running. But it's chances are come.
Other than this I would also want to suggest to confirm it that are those deals were deleted or not and for this what you can do is to navigate to deal pipeline view and click on Actions menu at right top.
Then click on restore deals and check in listing are those deals are listed there for restoration if yes then its clear that those deals were deleted.
I hope this will help you and if you find this helpful please mark it as a solution.
Can you please tell us how these deals are coming into your HubSpot account? You are creating them manually or coming through any integration or creating deal records through any workflow?