Different in simulation result of version 7.3 and 7.2

[garf]

Hi,

Apparently I noticed that simulation result from the version 7.3 can achieve daily specific yield 3.9 in the project site which I know it is unlikely to happen based on our experience and monitoring data.

And then I do the simulation using exactly the same setting but version 7.2 (my colleague laptop), and we found that the yield is about 10% lower compare to the version 7.3.

The simulation result of version 7.2 seem closer to the actual result.

May I know why is this happen? 

attached is the loss diagram of both cases. Thanks in advance for clarification...