Gmail does not work now

Although I make the preparation as your guide suggests, My gmail accounts can’t be log in on delta chat(ver1.20.5)

Do you get an error?

Yes, it always show like:async_native_tls: unexpected EOF, after my google accunt authorizing delta chat and then it starting log in.

i also notoriously experience issues with gmail + non-google email clients. i suspect they purposefully sabotage this use-cases. my honestest advice is to gradually abandon big G.

eof, possible reasons;
your connection not stable
your connection under attack of mitm and-or spy software bug