Hello,I confirm that sending a ping from my mobile phone originates a reply via bwfm0 (nothing in wg0) but it is never acknowledged by my phone (1 packet transmitted, 0 received). I also see what you noticed that seq0 is missing.
tcpdump -n -i wg015:44:58.522606 IP 90.167.219.193 > 44.27.132.76: ICMP echo request, id 31395, seq 1, length 64
tcpdump -n -i bwfm0 host 44.27.132.7615:44:58.522978 IP 44.27.132.76 > 90.167.219.193: ICMP echo reply, id 31395, seq 1, length 64
Regards.
