You will need to understand the sequence of the “Process PID”. At normal PID, your issue of not operating at 54% should be normal but the standard process PID of LS inverter operates as main frequency + PID. Please refer to the following diagram.
The highlighted part is where the main frequency is being added into PID calculation. For your symptom, please check your source setting at DRV-07. If it is set as keypad, main frequency is being input at DRV-01. If it is set as an analog input, please check how much the analog input is being recognized, either at V1 or I1. If you set this main frequency to 0, your indicated symptom will disappear.
Apart from setting the main frequency to 0, please refer to APP-28_PID mode select. Process PID is the default setting and you have an option to switch to Normal PID. The Normal PID will be PID operation without main frequency.