Sorry to hear you are having issues with MIDI clock, but I cannot reproduce this. MIDI clock is working correctly via DIN or USB on my H90 running 1.7.1.
Please note that you must set the clock source to MIDI Clock in the Tempo Menu and also set the MIDI Clock Source to either DIN or USB depending on your configuration. https://cdn.eventideaudio.com/manuals/h90/1.7.1/content/system-menu/midi.html
