Hi holnave so I had this exact issue with a customer environment last week, and when we escalated it to SolarWinds they advised there was a corruption in the application. We attempted to install Hotfix but that didn't resolve. In the end, the support rep advised us to UnInstall IPAM, and then re-install from a fresh download of the installer. This worked and the customer has full functionality again.
Not sure how you've got on since this post, but thought you might try it if you're still having issues.