Repo 'ubuntu stable-focal' is broken for armhf

[devizer]

for ubuntu stable-focal on ubuntu 20.04 an install fails

root@0967346c4bc8:/# apt-cache policy mono-complete
mono-complete:
  Installed: (none)
  Candidate: 6.12.0.147-0xamarin17+ubuntu2004b1
  Version table:
     6.12.0.147-0xamarin17+ubuntu2004b1 500
        500 https://download.mono-project.com/repo/ubuntu stable-focal/main armhf Packages
     6.8.0.105+dfsg-2 500
        500 http://ports.ubuntu.com/ubuntu-ports focal/universe armhf Packages

But bionic repo is ok. On ubuntu focal mono works properly for the stable-bionic repo no any installation issues on ubuntu 20.04

root@0967346c4bc8:/# apt-cache policy mono-complete
mono-complete:
  Installed: (none)
  Candidate: 6.12.0.200-0xamarin2+ubuntu1804b1
  Version table:
     6.12.0.200-0xamarin2+ubuntu1804b1 500
        500 https://download.mono-project.com/repo/ubuntu stable-bionic/main armhf Packages
     6.8.0.105+dfsg-2 500
        500 http://ports.ubuntu.com/ubuntu-ports focal/universe armhf Packages

The issue is present for armhf repo only. aarch64 and x64 are ok for ubuntu stable