Librem 5:Can't Update - 404 Not found

Unfortunately, when I checked for updates, I got the following error message:

Unable to download update:
E: https://repo.pureos.net/pureos amber-security/main arm64 libldap-common all 2.4.47+dfsg-3+deb10u3 is not (yet) available (404 Not Found [IP:138.201.228.45 443])

I tried a number of things, none of which worked. I ultimate checked the pureos.net server to see if that file and that version was actually hosted there (specificallly deb10u3). It was not. However, deb10u8 was, which refreshing the apt cache should have picked up. I downloaded the package index and checked it for that file in case it had been generated wrong, and everything looked good. For some reason, my Librem 5 wasn't updating the apt cache, even when I ran apt update via the terminal. I wasn't getting any errors either; only the one above when I actually tried to install updates (apt upgrade).

So, first I tried sudo apt clean, hoping that'd do the trick. Alas, no money.

Finally, I resorted to manually deleting the entire apt cache like so:

sudo rm -r /var/lib/apt/lists
sudo apt update

Refreshing the package cache that time took significantly longer (over a minute), but apt upgrade worked great after that.

I hope that helps!