[Ring] Deleted Conversation With New Message

[Nathan Royce]

Linux user1
Android user2

user2 requests user1
user1 accepts user2

user1 sends user2 message
user2 replies to user1 message

user1 deletes user2 conversation (not blocked. disappears from history)
user2 sends message to user1
user1 does not see any message

user1 dring log:
*****
1513055498.754|30778|ringaccount.cpp   :2381 ] Found peer device:
4a1<sanitized> account:be5<sanitized> CA:58f<sanitized>
[1513055498.754|30778|certstore.cpp     :516  ] Certificate check
failed with code: 322
* Certificate's issuer is not known
* Certificate was signed using an insecure algorithm

[1513055498.754|30778|ringaccount.cpp   :2280 ] [Account
31c<sanitized>] Discarding message from unauthorized peer
4a1<sanitized>.
*****

Expectation is that a new conversation history is created for user1.
It would NOT be created if user2 was blocked.
If user1 deletes the history, how can user2 request user1 as a contact
or know that messages are not being received by user1?