mariadb-client-10.5 and mariadb-server-10.5 (1:10.5.11+maria~hirsute) fail to install on Ubuntu 21.04 for arm64 - .deb files missing from official repos

MariaDB 10.5.11 packages "mariadb-client-10.5" and "mariadb-server-10.5" (version 1:10.5.11+maria~hirsute) fail to install on Ubuntu 21.04 for arm64 as the .deb files are missing from all the official repositories, although they are correctly declared in the "Packages" index file.

I have checked and tried this in at least 5 repos and it seems to be missing in all those I've tried, so it seems to be a generic problem for the arm64 architecture.

Kindly note that the amd64 versions of these .deb files are indeed present and downloable so, again, this issue seems to only affect arm64.

Please fix this problem and make both .deb packages files available.

Thank you!