This is occurring for me on focal with 3.36.1-0ubuntu0.20.04.0. It seems to affect all deb packages.
** Attachment added: "Screenshot from 2020-09-22 10-29-58.png" https://bugs.launchpad.net/ubuntu/+source/gnome-software/+bug/1662430/+attachment/5413202/+files/Screenshot%20from%202020-09-22%2010-29-58.png -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-software in Ubuntu. https://bugs.launchpad.net/bugs/1662430 Title: GNOME Software doesn't offer to update a .deb if it's already installed To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-software/+bug/1662430/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs