The main reason for the change you are seeing in results after upgrading to VE 188.8.131.52 is due to changes in the NCM Activities templates and/or SBEM.
VE 184.108.40.206 includes updated templates issued by BRE and also has an updated version of SBEM (version 4.1.d).
In general this will be the main factor for changes in the model. Details of the templates updates were not published by BRE but our own testing showed changes in areas such as DHW Rate, Heating and Cooling Setpoints/profiles, Occupancy (and profiles), Lighting gain profiles, Auxiliary Ventilation rate (and profile).
Refer to the related PDF for examples of these changes.
Please be aware IES are not able to investigate models on an individual basis, the above are examples of the kind of changes which have been made to the NCM Activities templates. It is up to the project owner to look into these changes and the impact on their own models where results are significantly different and have to be justified. The VE has a range of tools that can assist in doing this but the main recommendation would be to export Room Data information from VE 220.127.116.11 and 18.104.22.168 using Tabular Room Data, the text file exports can be copied into a spreadsheet and compared side by side to see details of changes between the models.
Full details of all changes in VE are documented in the Release Notes available to download on the IES website Download Centre and further information regarding changes to the NCM Activities templates and SBEM v4.1.d update are available from BRE.