1987 Acura Legend Clutch Master & slave cylinders

I've had the clutch master cylinder replaced about 2 weeks ago because of low engage/disengage point - like right on the floor board. After install, clutch was high until after driving 5-10 miles. Then came down but not to the floor and was shiftable. When parked overnight or for a few hours, the engage/disengage point would come back up to where it was just after the cylinder install. Driving would take it back down again. I don't see any leaks and I just had the clutch lines bleed yesterday and clutch point came back up Drove and shifted for about 10-15 miles through city traffic. The point went down a little until I got on the freeway and traveled about 15 more miles and the point went right back down to the floor. It sits awhile and comes back up. Been checking the fluid level and it doesn't seem to go down at all through all this.
I had the slave cylinder replaced about 4 years ago for the same problem. Could it need another slave cylinder replacement so soon? Is this a slave problem?