ICX6450 VLAN Dual-mode broken

[Smpltech]

I have a 6450 firmware ICX64R08030p and I have hit a wall for dual-mode vlans. There seem to be some limitations that a port can only placed in dual-mode if it is still untagged in the default vlan, which makes a big mess if you moved a port to another untagged vlan.

I can for instance do this:

vlan 5
tagged eth 1/1/20
int eth 1/1/20
dual-mode 1

So, starting 1/1/20 was untagged in the default vlan 1, I then tagged it in vlan 5, then went in to the interface and set it to dual-mode vlan 1. All worked as expected, its tagged in 5, untagged in 1. I can even dual-mode 10 and it successfully untags in 10.

However - if I go in to eth 1/1/1, which is the uplink port to the next switch, which is where I am programming from ssh. That port is currently untagged in vlan 99, which has a ve 99 with IP for me to program on. Most of the switch is untagged in vlan 1. I want to add several other tagged vlans to 1/1/1, but it does not let me add any. 

Procedure seems to be the port must be untagged in the default vlan, then you can tag it in as many vlans as you want, then go in to the interface and set it to dual-mode on some other vlan, which makes that the untagged vlan. BUT - you can only tag a port that is currently untagged in vlan 1, if it is untagged in any other vlan you cannot tag it in any other vlan. 

Note 1/1/1 is already untagged in vlan 99.

SSH@ICX6450-48P-Router(config-vlan-5)#tagged eth 1/1/1
error - port ethe 1/1/1 are not member of default vlan

It seems a port must first be untagged in default vlan 1, then it can be tagged in another vlan before it can be dual-mode, but if it is not in default vlan 1 it will never let you set it to dual-mode, nor tag it in any other vlans - it is like the port is locked in 1 vlan in a black hole.