Printer "scan to network" feature with vlans

[dgsmith]

We recently acquired some HP MFPs with scan to network functionality. Curiously, of the 3 printers, the only one which works fine with this function is the one not connected to our printers vlan - the other two, whilst passing the credentials "test" on the web config say they can't connect to the server when you try and use it on the printer. If I connect a workstation to the printers vlan and try to connect to our main server, it does indeed do so after authenticating.

 

I can't really figure out why the vlanned printers can't see or establish a connection to the server in order to save the scans to, nor think of what I could be missing or other diagnostics to try. Any advice?

[synaesthesia]

Assuming the gateway is correctly set and everything is routing as it should, they should just work; we have HP MFP's also with the same features with no such issues.