How to set up a 3com 4210 switch for multiple subnets?

Question

System administration

I inherited a subject. We wanted to set it up in port isolation mode, when two uplinks are allowed on it, each uplink has its own subnet, from each uplink 12 ports to the network. Two stupid switches in one half-smart, in fact.
Faced with an unexpected gag when the switch refuses to work with networks that are not built according to the principles of VLAN. Can this be overcome somehow, or is the piece of iron really so highly specialized?

Answer 1

Overcame. Reset to the factory and the usual breakdown into two vlans, like everyone else. The strange thing is that the usual reset to the factory through the webmord did not give such an effect - the errors still remained. But in the process we came across another reset method:
Which worked.