I can't subscribe to lemmy communities from friendica or mastodon

[pvagner]

Question

I am trying to follow this lemmy community https://rblind.com/c/main
I have either friendica account or a mastodon account.
I can't follow it no matter if I try from friendica or from mastodon.
I am actually not interested in following this other community at https://lemmy.world/c/technology
However I can't follow this one either.

Is this a known issue please?

Edit: Actually going to the following URL showcases the issue that page not found is displayed no matter if I am logged into the mastodon instance or not: https://mastodon.social/activitypub/externalInteraction?uri=https%3A%2F%2Flemmy.world%2Fc%2Ftechnology

[informapirata]

To help you, we need to know which instance both accounts belong to.

[pvagner]

Hello @informapirata

This is my friendica account: https://fedi.ml/profile/pvagner
This is my mastodon account: https://mastodon.sk/@pvagner
I'd like to subscribe to this lemmy community: https://rblind.com/c/main

For that matter recommend me a community under your control please, so you can inspect logs while trying to subscribe to it and we can try diagnosing it together.

Thanks for the help

Greetings

Peter