Cumulus Linux - Unable to run apt-get update - HTTP 500 on repository?

I've just installed Cumulus Linux 4.3.0 on an EdgeCore AS4610-54P switch. (4.3 is the last supported version on Broadcom-based switches - 4.4+ are for Mellanox switches only).

Upon logging in, I'm trying to run apt-get update to upgrade any packages.

However, I'm getting a HTTP 500 on the apt repo:

cumulus@cumulus:mgmt:~$ sudo apt update [sudo] password for cumulus: Ign:1 copy:/var/lib/cumulus/cumulus-local-apt-archive cumulus-local-apt-archive InRelease Get:2 copy:/var/lib/cumulus/cumulus-local-apt-archive cumulus-local-apt-archive Release [1,115 B] Ign:3 copy:/var/lib/cumulus/cumulus-local-apt-archive cumulus-local-apt-archive Release.gpg Get:4 copy:/var/lib/cumulus/cumulus-local-apt-archive cumulus-local-apt-archive/main armel Packages [18.2 kB] Err:5 http://apt.cumulusnetworks.com/repo CumulusLinux-4-latest InRelease 500 Internal Server Error [IP: 13.35.142.70 80] Fetched 19.3 kB in 1s (21.6 kB/s) Reading package lists... Done Building dependency tree Reading state information... Done All packages are up to date. W: Failed to fetch http://apt.cumulusnetworks.com/repo/dists/CumulusLinux-4-latest/InRelease 500 Internal Server Error [IP: 13.35.142.70 80] W: Some index files failed to download. They have been ignored, or old ones used instead. 

Does anybody know if there is something going on with Cumulus (NVidia/Mellanoxes) update repositories, or if there's some way of working around this?

Does it work for anybody else?