Oh joy, now supervisor has decided to remove the community addons on its own. I have no problem getting to either the hass io offical repository or the community repository on two different computers on my network, also on two different browsers.
21-03-24 22:36:24 INFO (MainThread) [supervisor.store.git] Cloning add-on https://github.com/hassio-addons/repository repository
21-03-24 22:36:24 ERROR (MainThread) [supervisor.store.git] Can't clone https://github.com/hassio-addons/repository repository: Cmd('git') failed due to: exit code(128)
cmdline: git clone --depth=1 --recursive --shallow-submodules -v https://github.com/hassio-addons/repository /data/addons/git/a0d7b954
stderr: 'Cloning into '/data/addons/git/a0d7b954'...
fatal: unable to access 'https://github.com/hassio-addons/repository/': Failed to connect to github.com port 443: Connection refused
'.
21-03-24 22:36:24 INFO (MainThread) [supervisor.resolution.module] Create new issue IssueType.FATAL_ERROR - ContextType.STORE / a0d7b954
21-03-24 22:36:24 INFO (MainThread) [supervisor.resolution.module] Create new suggestion SuggestionType.EXECUTE_REMOVE - ContextType.STORE / a0d7b954
21-03-24 22:36:24 INFO (MainThread) [supervisor.resolution.fixups.store_execute_remove] Remove invalid Store: a0d7b954
21-03-24 22:36:24 INFO (MainThread) [supervisor.store.git] Removing custom add-on repository https://github.com/hassio-addons/repository