What is the pedal height from the floor? What is the pedal freeplay before it starts depressing the piston? Pedal height should be 7.3-7.5", and freeplay should b3 8-16mm. Disengagement height should be 1.38" above the hard floor.

If all those are good when the adjustments are correct, the only other causes are a bad clutch/pressure plate or leaking seals in the master/slave cylinders.

Not responsible for advice not taken...