The Install button is missing when trying to upgrade a app from a deb file using the Ubuntu Software GUI after upgrading to Ubuntu 20.04

I have a Dell XPS 13 7390 that came with Ubuntu 18.04. It recently prompted me to upgrade to 20.04, so I did.

Some of my software, checks for updates when it starts, one example is DBeaver. I have found if I download a deb file for applications that existed before the upgrade, the "Ubuntu Software" GUI opens but with no install button, it only has a Remove button:

Before the upgrade, I would install new versions of my applications updates using a Install button in the "Ubuntu Software" GUI.

Anyone know a way to fix this and get back the Install button.

Notes:

• I tried removing the application and re-installing. This doesn't fix it, the next update is also missing the Install button, so updating is hard.
• I know I could try a different way of installing, e.g. dpkg on the CLI but I want to solve this problem without a workaround.