According to your description Asterisk don't fully support SIP over
WebSockets (draft-ibc-sipcore-sip-websocket-02).
If it was the case it would handle AoR if address equal to
'df7jal23ls0d.invalid'.
- The option request is not received because it's sent to your 'hard-
coded IP'+port and for sure sipML5 is not listening to that port.
- The 200OK is received because it's sent back using the same
connection use to send the request (REGISTER). A server supporting SIP
over WebSocket have to use this same connection for incoming requests
(e.g. OPTIONS, INVITE, ...)