Ubuntu 20.04 here. Recently I started to notice odd behaviour of Software Updater (it happened two or three times already). Software Updater window pops up, telling me that there are some updates to install. I install these updates, finally a window appears telling me that my software is up-to-date and I close that window by clicking OK. But after a short time, the same Software Updater window (ie. the one telling me that the software is up-to-date) appears again, and I again need to close it by clicking OK. This is repeating until I do what follows:
I open Synaptic and in Synaptic I can see that there are some more updates available (that did not show up in Software Updater). After I update these packages from Synaptic, the Software Updater window telling me that my software is up-to-date stops popping up.
So it looks like the window is triggered because there are still some updates to install, but the window doesn't show these updates and instead tells me that everything is up-to-date. Why? Is it a bug?
My update settings are configured as follows: Subscribe to -> all updates, Update check frequency -> daily, What to do for security updates -> immediately notify, What to do for other updates -> immediately notify. So everything should be shown in Software Updater, and basically it was so until recently...