I just picked up a Moes Zigbee smart knob (Model ERS-10TZBVK-AA) and I can’t get it to pair with my Sonoff Zigbee dongle.
I push the button on the smart knob for 6 seconds (as the directions suggest) and the LED blinks 2-3 times and then stops.
Others here seem to have gotten the knob to pair, but no luck for me.
Any tips?
I’ve had that a few times with other devices. What got them working eventually was:
It should then go into pairing mode properly. (No not the last bit. The first five steps have worked for me several times. Honestly. 
)
Apparently not for me, sigh. Followed your steps, but still no pairing.
Also take actions to avoid EMF interference (like using a long USB extension cable to a USB 2.0 port and not USB 3.0 port) → Guide for Zigbee interference avoidance and network range/coverage optimization
Eric don’t know if you solved this - I had the same problem! and it was driving me made. Apparently this device is very sensitive to voltage - I put in a fresh battery and it paired first time! I found these instructions Pairing instructions for ERS-10TZBVK-AA by wildekek · Pull Request #1212 · Koenkk/zigbee2mqtt.io (github.com)
After about 6 or 7 extra tries (removing the battery, etc.) I finally got it to pair. I’ll keep your solution in mind when I pair the other knobs in the future.
I’m very curious why this solution is the only thing that worked for me. I bought a bunch of devices a few weeks ago and was never able to get them to connect until now. Thank you!
this was the solution. new battery fixed it.
Can confirm. I put a brand new dollar-store battery in a Moes Zigbee Knob and it refused to pair even after many attempts. I swapped the battery with a new named brand one, and it paired right away.
The annoying aspect is that with the cheap / low voltage battery it still acts like it’s pairing and flashes the same lights, it just doesn’t work.