Ok, SOLUTION FOLLOWS
(took me 2-3 days of reverse-engineering VS internals and monitoring registry / disk access and sh*t):
Create anDWORD (32-bit) valuecalledEnabledand set it to0under:
HKCUSOFTWAREMicrosoftVisualStudio16.0_6cf1d688RoslynFeaturesSymbolSearch
The 'RoslynFeaturesSymbolSearch' keys have to be created as well. （自已创建啊）The '16.0_6cf1d688' version number might be different on your machine.（有可能不一样哦）
Hope this helps,
Lars Wilhelmsen