Zer 0 ne T w ORE: https://exquisite.social/@p01/115922537758941853
For the benefit of anyone with a similar technicality ('not being able to engage with accounts from other instances'). if any.
I figured, what the problem was, for me.
I much work with tabs. So instead clicking on the profile directly, I opened it with right mouse click in a new one. At least with privacy oriented browsers this doesn't work. The new tab didn't establish the link to (exquisite.social in) the original tap. To mastodon.social I looked like an outsider.
Interestingly, it does work as long as the new tabs links to the same server, in my case exquisite.social. That is why I didn't establish the connection. It always worked well for me.
Well, too, I was on mastodon.social, then. It works still now - for exquisite.social. It, too works across them, but (at least for privacy oriented browsers) only within the same tab.
(Just to complete the observation. If, first, I go within the same tab to mastodon.social, then I can open in new tabs all other mastodon.social accounts from there.
So my personal observation: In the Fediverse tabs works as long as original and new tab are hosted by the same instance. Changing from one instance to an other only in the same tab)
Should you encounter something similar, or be approached by someone who does - give it a try?
Thank you for the feedback I got on this observation. Very much too, for the same day response by exquisite.social in exchange with mastodon.social. Indeed!