Have a look at the improvements to the Encoder Bar and Encoder Readout and Resolution. This link should take you directly to the section in the Release Notes: https://help2.malighting.com/P…/1.5#toc_header_anchor_13
Your picture shows your Encoder Bar Readout in the bottom left set to "Natural."
"Natural" is a new feature allowing you to use the defined Readouts per Attribute.
In new shows and migrated show the Gobo Wheels have a Readout of "Physical" as the default. You can find and change these settings in the Attribute List of the Patch window.
I suspect your problem relates to a missing physical range for the Attribute you are using. This range is defined in the Fixture Type. If a physical range is 10 to 10, or 0 to 0, then there's no range. Since there is no physical range naturally there will be no change of the output. Try re-testing the challenge you face by changing your encoder bar Readout to something else (e.g. Percent) and see if your encoder now controls the Attribute. Then you've basically confirmed that the physical range for the Gobo channel or ChannelFunction might have the wrong physical range definition in the Fixture Type.