I did the same, no solution on W10 TP. I guess we should insist to MS to fix this with a software patch that reasigns the Mic for speaker mode to the main Mic (the one you use for normal calls) or maybe other Mic (930 has lots of Mics....)
This might be the only way, there must be a software fix, as it was for the purpleish screen... Where could we insist for this?