I had less time to test, so this comes really late - The Problem exists since 2 weeks:
I use an ex6150v2 to connect the Tesmesh to the Internet (1GBit ETH-Port manually assigned as WAN): I used openwrt 19.07.4 with libremesh 20.09 and got no IP V4 address. (And no: the babeld is running ;-) It is another Problem than in snapshot - which is solved atm).
The connected Meshnotes give the Mobile Device an ip v4, so there it is working - but not connected to the "Gateway" (Neither in pa nor in apname Mode). So I checked and reverted the WAN Port to an LAN Port - the connected PC does also get any ip v4 address.
I compiled new with 19.07 (as newly advised by Ilario) and libremesh (not branched to 20.09)
Still the same behavior.

Any thoughts on this?

Regards,
Andy