In Amethyst I can see my 0xchat's. I think your client must support NIP-44 to receive gift-wrapped messages from any other client.

"Gift-Wrapped DM is default and recommended DM type for 0xChat. By using Gift-Wrapped for event messages, it minimizes metadata leakage. Not only is the message content encrypted, but the sender and the timestamp are also concealed. Moreover, the encryption algorithm employed is the latest audited NIP-44 algorithm".