You will have two resolutions if your slider carriage brake is not functioning as designed.
If you have access to a 5/64 hex wrench it is an easy swap to remove the two bolts that attach the brake assembly to the carriage. If this is an option you are comfortable with reach out to customer support to request a replacement brake assembly.
Alternately, if you would prefer the brake repaired in house you can reach out to customer support to begin the repair process. If the issues is due to a manufacture defect in the build of your slider, we are happy to provide you with a prepaid postage label to send the carriage in for repair.