KVM fusionhub packet frag?

Wondering if the frag issue is back for KVM fusion hubs in 8.1.2b01 build 4996, seeing quite a high number of fragmented packets over VDSL based wans even when I set the MSS to 1350 or below.

It’s often in excess of 1K PPS on each wan needing fragmentation.

The largest packet I seem to be able to send over speedfusion to either the fusionhub i’m connected to without fragmentation is 1320bytes this seems rather low.

One Fusionhub is VMware the other is on KVM the fusion hubs are hosted on 2 different providers, both standard MTU of 1500,

WAN1 here will be 1500, WAN2 will either be 1500 or 1492, encryption is off, speedfusion is set to respect the DF bit.

Balance 20x at this end.

sending 1350 bytes to with df bit set

8.1.2b02 - fails
8.1.1 - fails
8.1.0 - works although i see a lot of fragmentation on the wans (I think this version had an issue with KVM and packet frag and needs a special build on the Fusionhub side)
8.0.2 - Works but doesn’t show fragmentation info in the wan stats

Something seems off here, the MTU inside the SF tunnel seems far too low for WAN MTU - SF overhead. (Note encryption is off)