Sultan RS Classic (Can't pay tax for it)

I noticed on the LSRS app I can no longer pay tax for my Sultan RS Classic (Which I have previously paid Tax for) I have bought the Vehicle from Luxury Autos.

On my vehicles owned, I can see I still have and own my Sultan RS Classic, but on the LSRS App, the only vehicle I can pay Tax for is the lawn mower.

https://i.imgur.com/gETZ7Ky.png
https://i.imgur.com/rbT5h2c.png