High latency on macOS Sierra

[dragonx]

I'm working with a custom btle device which supports a ping command written to a characteristic. It sends a ping response in a subsequent notify on the same characteristic, though there may be a 1 or 2 packet delay.

On OSX El Capitan, these worked more or less as expected. I expected latencies between 60ms-90ms because of the packet interval, and I was usually getting 110ms. A little off but not too bad.

After upgrading to macOS Sierra (nothing else changed, as I was already suspecting Sierra since this repro'd on a different machine) I started getting latencies of 300-400+ms.

It looks like the btle packets are coming in, but delayed, maybe because they are being buffered somewhere. Has anyone else seen this?