I notice that your case is still running so please continue with it. I believe the engineer has requested to run a few tools for measurements.
For that SQL thing. It is not really strange. SQL itself is known to "eat" all the memory it can get. (For example, if you have a VM that can grow its memory at request and that is running a SQL box...
). But it seems that in your case when it takes that memory (although only 3.5 GB) the system starts to slow-down. Does the B&R server has enough RAM? But it could also be an underlying disk issue.
Anyway, I hope that our engineers find something after the results of the tools