As you can see from the announcement thread, the issue was fixed in version 2.0.60. So you need to manually update to that version, and automatic updates should work afterwards.

Does It say that you already have installed the same or higher version? Or is it the interrupted updating bar and then a window saying that you do not have certain components installed?

If it is the latter the next time Galaxy is launched you will see that the game was installed to the higher version doesn't matter the message or the supposedly nterrupted updating process

If it is the former (It happened to me in the previous preview version, the beta of the beta, I guess) I solved it deleting physically the Galaxy executable and instead of updating I downloaded the online installer, overwriting the Galaxy Folder. It worked, at least at my second try.

Those are ony workarounds, Indeed the updating process is weird and glitchy.

I can confirm this works but Gog should have directly stated that you need to manually download Galaxy again and install it.

Indeed this issue is fixed in the 2.0.60 version. In fact, it was fixed in the 2.0.59 beta too. For ages I hadn't seen the automatic update working, but I installed the 2.0.59 and it actually automatically and successfully updated to 2.0.60.
But in case you are on an older version, as stated in the posts above, you'll need to download manually. After that it should work.

Ah, I hadn't read that thread. Thanks.

Annoying to uninstall again since GOG does the "building your library" thing, but hopefully it's the last time.

No need to uninstall. Just run the update right after Windows start before you started the old Galaxy version.