Not uncommon after new clutch disc is installed.
Could be air in the system, doesn't take much with new clutch disc, as clutch disc wears down a small bit of air doesn't matter as much.
The transmission always spins at rear wheel speed, there is no disconnect for that, so when you are stopped the transmission is at 0 RPMs
Engine idling is at 700RPMs
The clutch disconnects engine RPMs from transmission RPMs so you can shift gears
The clutch disc is sandwiched between the flywheel and pressure plate.
Flywheel and pressure plate always spin at engine RPM
Clutch disc is connected to input shaft of transmission so always spins at transmission RPM(except in Neutral)
When slave pushes in on the pressure plate it releases the sandwich pressure on the clutch disc allowing it and input shaft RPMs to be different than engine RPMs.
With new and thick clutch disc the release of all pressure means slave must extend fully
If clutch disc pressure is not fully released then clutch disc will rub on the 700 RPM flywheel and/or pressure plate and be hard to slow down to 0 RPMs(stopped rear wheel).
You have a 10" clutch disc you are trying to slow down with a 4" syncro, thats what the syncro does, it matches input shaft RPM with output shaft(rear wheel) RPMs
As you push shifter into 1st the syncro slows down the input shaft to 0 RPMs to match transmission RPMs
So when stopped with engine idling and clutch disc not fully release it would be hard to get into 1st gear.
When moving and shifting gears the RPM matching is easier when there is a little clutch disc rubbing, but as you said it is noticeable
Long shot is Pilot Bearing is bad, pilot bearing is in the flywheel/crank shaft, it supports the end of the input shaft, it allows flywheel to spin at engine RPMs and input shaft to spin at different RPMs, if this bearing is bad then input shaft RPM would stay at engine RPM and be hard to slow down.
But I would expect a noise when you were in 1st gear and stopped with clutch pedal down, that 700RPM to 0RPM would make a bad bearing "cry"
