Clutch pedal travel suddenly changed - now bite point in last 2 inches towards floor

Afternoon
Title says it all really.
96' Defender 300 TDi 200k miles
Clutch master and slave cylinders replaced Sept '23
Clutch replaced Oct and Nov '23 (Don't ask....)

Today while changing gear the clutch pedal travel and bite point suddenly changed. There was no clunking or any associated noise, no problem selecting gear, no clutch slippage etc BUT from having a bite point pretty much mid point of travel it change to being much closer to the floor.

The pedal travel is not 'sloppy' or 'spongy'- I can just feel the spring resistance in the 1st section, then feel the bite point and clutch disengage, change gear, then reverse the pedal travel til the return spring takes over.

Doesn't make any difference if the pedal is pumped several times

Checked the fluid reservoir - full.
There does appear to be a gentle 'weep' of fluid on the piston rod, but not so as you would really know, and as I said the fluid reservoir is full.

Having looked through the Forum it would appear that we might have air in the system? If there is what would this point to? As there seems to be a bit of wetness on the piston might there be air entering that way?

Any pointers please before we go ahead with replacing master cylinder (again...)

Thank you

Has your shaft adjusting nut come loose ??

If fluid can get out air can get in.
It is a sad thing today the quality of some spare parts can be poor. Some are even fakes in a well known makers box colours.

Bleed the clutch slave cylinder.
place a drip tray on floor under slave cylinder, then slacken off bleed nipple (just slacken it off do not open it) then put a piece of pipe on the bleed nipple that reaches up to the top of inner wing and into a container, remove the clutch fluid reservoir top, then open the bleed nipple and "gently" press the clutch pedal once, let pedal return then top up the reservoir, repeat several times topping up after each press until clean fluid is coming from pipe, nip up the bleed nipple top up reservoir and replace the top, remove bleed pipe catching the fluid that remains in the pipe in the drip tray, very easy to do this way on your own. Hardest part of the job is getting the top off the reservoir and the dust cap off the bleed nipple, I use a small ring spanner to slacken the nipple and leave it on the nipple before fitting the pipe. But ultimately it sounds like you will need to replace the master cylinder it it is starting to leak.

Thanks everyone - all in all a PITA.