This sounds like a post processor question

Your old work flow used to be:

“2D Design” - CAD
“2D Design” - CAM
“2D Design” - CAM post processor to Roland CNC

Your current workflow is:
“2D Design” - CAD
“CamBam” - CAM
“CamBam” - CAM post processor to John Brennan CNC

The main reason I guess is that 2D Design does not list your new machine on the post processor list?

If you want to stay all inside 2D Design software you would have to try a few PPs on the list (assuming there is a list) to see if they run your machine or get someone to write a custom PP for your new machine.

Work around might be use 2D Design CAM to post out gcode with the nearest compatible PP and hand edit (find replace) any offending commands. This would only work if there were minor differences and has to be done for every gcode file created.

Ask2D Design if they have a PP for your new machine and/or tell the machine supplier that you need a PP that runs inside 2D Design.

Another idea is to migrate to Fusion360 as this has a long list of PPs and has CAD CAM combined and is free for education use.