I've found this recent entry in ufw.log:
RaspberryPi kernel: [1046588.133562] [UFW BLOCK] IN=wlan0 OUT= MAC=mac_address SRC=0.0.0.0 DST=126.96.36.199 LEN=32 TOS=0x00 PREC=0xC0 TTL=1 ID=0 DF PROTO=2
My default ufw policy is to deny incoming and allow outgoing. In the past i've blocked incoming connections from 188.8.131.52/24 since the router(?) was spamming my ufw.log with such entries. However, this entry is new.