Have tried as you suggested, and confirmed it works.

No issue on 1.4-rolling-202107191536 and later.

I think it is already fixed in T3674

@ramaxlo You can try to set this workaround:

Have tried, but no luck.

Want to test latest rolling iso, but equuleus seems to be stuck at vyos-1.3-beta-202107121144-amd64.iso which doesn't have this fix yet.

PR https://github.com/vyos/vyos-1x/pull/933

Will be available in the next 1.3 beta release.

PR https://github.com/vyos/vyatta-cfg-quagga/pull/85

set protocols static table 1 route6 ::/0 next-hop fe80::11 interface eth0
commit

To reproduce, without the "interface" option

set protocols static table 1 route6 ::/0 next-hop fe80::11
commit

Also, the bug still present, fix for which I sent above in diff

vyos@r5-1.3-myb# compare 
[edit interfaces]
+vxlan vxlan0 {
+    mtu 1430
+    remote fe80::2
+    source-address fe80::3
+    source-interface eth0
+    vni 0
+}
[edit]
vyos@r5-1.3-myb# commit
WARNING: RFC7348 recommends VXLAN tunnels preserve a 1500 byte MTU

@c-po It seems doesn't work