h.264+ has been reported as an issue with Blue Iris since camera manufacturers started using it.Just an update, both cameras still going strong since the problematic one had its disconnect.
One thing I changed was to enable "H.264+" which is supposed to be a compressed version that decreased the bandwidth used by rtsp of the faulty camera as well as change both cameras ntp refresh rate (against my server pc) to 600 minutes instead of 60.
Fingers crossed.
Seems to be some kind of incompatibility with Intel QuickSync that causes the issue.