5.1 surround sound didn't fix the bug for me, but 32-bit did, however, playing with a bunch of units in 32-bit has way more lag than 64-bit, so for now i'll wait for a fix, hopefully it comes soon :(

Still having the main problem, the stuttering in 64-bit only, and in 7.1 and 5.1 surround sound. Only fix is changing to 32-bit. Hope this problem gets fixed eventually.

Just realised that this problem is the same as referenced here : https://feedback.bistudio.com/T122385, I don't know how to close this report, it is unnecessary, as the problem is being worked on there.