Wow, that's interesting. We have had other users have problems connecting to their H9s on Sierra or High Sierra (https://www.eventideaudio.com/community/forum/stompboxes/h9-will-not-connect-new-macbook-pro-sierra).
A few of them were kind enough to collect Bluetooth logs showing what happened when they tried to connect their Macs to their H9s, and we opened up a bug report with Apple and submitted their Bluetooth logs as part of the bug report.
I wonder if your solution would help them, although I think they were saying they could never get their Macs to connect to their H9s. I'll share your post in that thread…
