open https://twitter.com
visit twitter

Probably just the Fenix version of https://bugzilla.mozilla.org/show_bug.cgi?id=1665368
maybe same bug I ve just reported?
https://github.com/mozilla-mobile/fenix/issues/15289
Current workarounds:
open mobile.twitter.com in a private tab
open twitter.com as a desktop site
mobile.twitter.com works in normal tab
same with linkedin

This is fixed. Closing.