I'm developing a custom stratum server that seems to be working fine now (miners submit valid work), but t-rex is outputting these messages constantly:

WARN: New iteration find shares for device [ID=0, GPU #0]: job_id=2e61

What could be the cause? I don't get that connecting to normal stratum servers.

EDIT: Sorry, I realized there were extra warnings too with protocol debugging enabled. That's happening on other servers, too. Seems like it warns about receiving the same notify twice, is that somehow bad?