Three or four days ago I had a set of low-G Aquila "Red Series" strings installed on a Martin 1T tenor ukulele. (I had it done at the store because the bridge pins were giving me fits.) I have new Gotoh tuning pegs with planetary gearing.
Three of the four strings have settled in, but the C continues to drop in pitch after 30 seconds of playing. I noticed that they'd left too much slack in the C when they wound it on the tuning peg, and it had wound onto itself, which I've read is not what you want. I've corrected that, but the string is still stretching. The tuning peg is definitely not slipping under the tension.
I guess it's possible something may be settling in at the bridge-pin end....
Should I just give this a few more days?