You likely didn’t set Min Power. On a Ruida controller (and most DSPs) the controller starts using ‘Min Power’, and as the speed passes a setting called the Start Speed (or corner speed), it ramps up toward Max Power. If your cut never goes faster than that Start Speed setting, it only uses the Min Power, not the max. The default for this on a Ruida controller is 10mm/sec, so that’s the most likely reason you’re not getting power.
If cutting slowly, set Min and Max power to the same number.