Issues syncing Zoom F6 and BMPCC4K with Timecode

'm running into a syncing issue with my newly purchased F6.
I did a simple test today - my setup was the following:
F6 connected to the BMPCC4K, the BMPCC4K was showing EXT TC. The microphone (Rode VideoMic Pro+) was mounted on the camera, connected to the F6, the camera was placed like 1.5 meters (5 feet) away from me. The camera was recording audio from the inbuilt microphones, so the two microphones were virtually the same distance away from me.
The F6 Timecode was set to Mode: Int Free Run, TC Out: Always. It seems that the BMPCC4K was OK with this configuration.
However once I did a simple "clap test" and synced the audio in Resolve I've noticed that there's exactly 1 frame difference: the F6 audio was exactly 1 frame ahead.

Screenshot 2020-08-09 at 10.11.29.png (201.45 KiB) Viewed 762 times

Any ideas on what I am doing wrong?
I'm using the 16.3 Beta is that matters...

You synced by audio, not timecode?

I synced by timecode. Did it twice just to make sure.

Got it.

Just to confirm (as I can't see the zoom level in the posted image), the audio is one full frame off? It's not a sub-frame difference?