secondary IP on wg0 fails

[lejeczek]

Hi guys.

I'm experiencing a pretty weird wireguard, or perhaps 
kernel/OS stack bits behavior.

I have three nodes which all can ping each other on wg0's 
IPs but when I add a secondary IP:

-> $ ip addr add 10.0.0.226/24 dev wg0

it gets weird, namely, say when that sec IP is on
A -> B ping returns; C ping waits, no errors, no return
B -> both C & A pings return
C -> neither A nor B ping returns

I'm on CentOS with 4.18.0-301.1.el8.x86_64.
All three nodes are virtually identical kvm VMs.

any suggestions as to what is not working here or how to 
troubleshoot are vey appreciated.
many thanks, L.