What is the origin of messages OPS1371I?
OPS1371I is the default message id when you use the OPSWTO or ADDRESS WTO commands.
This means the messages you are seeing are user messages, that is, some rule or user REXX program written at your site is creating them.
For example, if you execute the TSO command below:
tso opswto Text('Test message')
t will produce a message like below:
OPS1371I TEST MESSAGE
As I didn't specify a message id, OPS assumed the value OPS1371I. If I change my command as below:
tso opswto Text('Test message') msgid(MYMSGID)
The message produced will be:
MYMSGID TEST MESSAGE
So, as I said before, the OPS1371I messages you are seeing are being produced by user code created at your site that didn't specify a msgid when issuing the WTO.