I have exactly the same problem. I tried to change the following coin settings:
RPC Type: POW, POS
RPC via curl: On, Off
Has submitblock: On, Off
Txmessage: On, Off
The effect was nothing
I think Blocknotify in coin daemon is working pproperly -- there are no any errors in coin daemon debug.log.
Is there any ideas how to solve it? I found many messages in forum describing the samr problem, but all of them has no answers.