Bug #16823
Updated by Marcos M 7 days ago
When a VXLAN interface is inside a bridge it should inherit the bridges mtu and it does under settings and on creation, however seemingly randomly and always on reboot it will reset to 1450. The interface can be fixed by manually saving it and applying it within the webui.
https://forum.netgate.com/topic/200196/vxlan-over-wireguard.-unexpected-mtu-reset-bug-pfsense