I flushed the clutch this weekend to (hopefully) address a change in the feel of it.

The clutch feels spongy, soft, and almost like it doesn't engage very firmly. It feels 'different' from what it was.

There is no evidence of it slipping either under any acceleration. When parked with the e-brake on and in 3rd gear it stalls immediately when letting the clutch out (starts to grab about 1/2 way up).

When we were at Sebring earlier this year (after my instructor drove) and parked in the pit stall - I noticed that the clutch pedal was stuck to the floor. I didn't think anything of it at the time - as it popped right back up with a pull from the toe - and the car performed flawlessly for the rest of the weekend. Maybe that was a sign of something.

There are no visible leaks anywhere that I can see. Car is an 07 997 base 6MT with 22K miles.

Could this be a slave issue? Master issue? Potential pressure plate (I hope not).