It sounds like you might be encountering an issue with the order of constraints or the specific settings of your transform constraint. Here are a few steps you can take to troubleshoot and potentially resolve the issue:
Check Constraint Order: Ensure that the transform constraint is applied in the correct order. Constraints are calculated from top to bottom in the constraints node, so if the transform constraint is not in the right position, it might not work as expected. You can manually reorder the constraints or use the reset button to see if it helps. More information on constraint order can be found here.
Verify Bone Hierarchy: Make sure that the constrained bone is not a child of the target bone. If it is, the transform constraint will not work properly.
Adjust Mix Settings: Ensure that the mix settings for the transform constraint are set correctly. If the mix is between 0 and 100, it might cause unexpected behavior. Setting the mix to 100% might resolve the issue.
Check for Other Constraints: Verify that there are no other constraints affecting the bones in question. Sometimes, other constraints can override the transform constraint, causing it to appear as if it is not working.
Local and Relative Settings: If you are adjusting rotation, make sure to check the "Local" and "Relative" options in the transform constraint settings. This can sometimes resolve issues with rotation not being applied correctly.
If these steps do not resolve the issue, please provide more details or screenshots of your constraint settings and bone hierarchy for further assistance.
