Looks like a nice little unit. There isn’t much you can wire wrong really, just connect the single phase input between any two of r s and t and the motor across u v w, the link the motor to be star or delta as required.
Don’t get hooked up on the voltages, as its current and frequency that drives motors not volts.
As its giving an output and turning the motor its unlikely to be knackered, so I would put money on it being setup wrong.
The unit has a variable output either from an external input (variable resistor) or using the keypad. In the settings I’d check this first so that a) the output is set it to be by the keypad and b) the output is set it to 100% from the keypad Also check the max output frequency is set to 50hz .
Inverters usually ask for a motor size too to limit the current to a safe value to protect the motor. This might be set too low so check that too.
If the manual is chinglish this might take some time I’m afraid.