What’s the DTH you are using for the virtual switch?
I ask because there was a platform change in that timeframe and the stateless virtual Switches started getting goofy. Many people had to change to the “simulated switch“ DTH in order to get things working again.
Not sure if that’s relevant, but just thought I would mention it. This was an undocumented platform change, and we’re still not entirely sure what happened, just what the workaround is.