Z-Wave Network Stability Adversely Impacted, Seemingly After Having Added Aeotec Home Energy Monitor

I do not have an official update at this time yet, however we recently discovered that the new firmware version 2.5.2 resolved a separate issue which affected S2 devices pairing properly (the T3000 specifically). Z-wave updates were made in 2.5.2.

Can you try updating to 2.5.2 via these instructions and test? Any change?