https://armbian.lv.auroradev.org/apt/pool/bullseye-utils/h/htop/
Nothing there.
Just running basic ...
apt-get update && apt-get upgrade
... upon initial install, and it fails with "failed to fetch" (404) from whatever apt.armbian.com mirror it selects (of 2 or 3 observed).
Held it back with apt-mark, removed it, and built from source using deb-src. Doesn't seem to be any problems or issues running htop built from deb-src, so, not sure why its needed in the Armbian source repositories ???