Where you able to look into this? Do you have a support case for this?
Just checking because mine support case is really taking some time now.
Kind regards
Do you have by any change Blocking intra-vlan enabled on the client
vlan? I have a similar problem, but I'm not using split interface. But
the problem looks the same. We are now looking with suport into this
problem, we are using FortiGate 7.4.9 and ...
