Octavia Scout 2016 clutch

My 2016 Octavia Scout has a slow to return, kind of notchy clutch pedal. The pedal returns half way then pops back up and hits a stop, doesn't happen all the time, but it's fair to say there is always some hesitation in the return at the upper limits. Very rarely it's stayed in the last 25% of its downwards travel and I've lost the gear indicator. On these occasions I've tapped the edge of the pedal with my foot, not pulled it back up, and this has made it pop back up most of the time. The pedal feels firm and has good return force most of the time. Clutch fluid level was midway between limits so I topped up and bled from the torque limiter block. No air bubbles came out but mucky looking fluid with small dark particles in it. Fluid is now nice and clear. Can't see any fluid leak from the MC under the pedal. The car drive without any sign of an issue next day, but returned to usual the following day. Am I likely looking at an extortionate CSC job ? Appreciate any help.