OPC path inconsistently working in UDT definition

In my UDT instances, some tags in the definition show null in the OpcItmePath while others are not. They are all configured the same way

All the parameters being passed are valid OPC paths

This tag is showing null in the OPC path

This tag is working correctly

Can someone please tell me how to fix this please?

On the OPC Item Path have you configured them to be expressions that link to your parameters.
It looks like the first has no path and has errored while the second you’ve selected the OPC path correctly.

Can you show the expression in UDT

Okay, I figured out what the issue was, If the parameter name contains a - then the value does not get passed through. This has to be a bug that needs to be fixed.

No, not a bug. Or rather the bug is that Ignition allowed you to use a hyphen in a parameter name.