I have reported this to Autodesk (CaseNo:17777832) and they have acknowledged they can repeat the problem.

Currently no usable workaround other than to carry on with 2021.

The post you show looks like the one I did for HK Laser - it requires the script to run to convert the output. Originally it was set up to do this using a Process as I couldn't get the customNC to do all the things required for the machine.