I had this happen to me when my flannel and cni0 inet addresses were out of sync. Bringing down the cni0 bridge made it resync for me:

ifconfig cni0 down
brctl delbr cni0

Or if that doesn't work:

sudo ip link delete br0 type bridge

Hope that helps.

I had this happen to me when my flannel and cni0 inet addresses were out of sync. Bringing down the cni0 bridge made it resync for me:

ifconfig cni0 down
brctl delbr cni0

Or if that doesn't work:

sudo ip link delete cni0 type bridge

Hope that helps.