I already in v57 had to set privacy.firstparty.isolate.restrict_opener_access to false in about:config because every site is wanting me to login all the time...

I already in v57 had to set privacy.firstparty.isolate.restrict_opener_access to false in about:config because every site is wanting me to login all the time... (At least I assume that was the reason.) I did toggle privacy.firstparty.isolate to true, though.