thank you, I was starting to wonder if I was alone with this problem and it was just in my head. Another thing that came to mind was when I heard Jake say that by playing with one instrument (mainly) you learn the reactions of that instrument and you learn to adjust to it. I thought maybe that was what I needed to do.
This in spades!
My fingers pluck the strings of my bass at 90deg(ish) to the strings( angle of the finger to the string). Call it 60degrees for the guitar, more 45degrees for the ukulele. They're held differently. Consequently, different areas of my fingertip pads have different rough spots. Most of the time, this matters not. Sometimes, such as 'stroking' the strings, the edge of my 'bass pad' catches, and I get a scratchy. I just create more of a hook shape and get on with it.
The problem, such as it is, seems worse when practising on my own and I tend more toward the quiet end of things so as not to disturb the family. When noodling about with friends, the volume goes up and it really isn't noticeable.
The worse sound my fingers make is when I catch the edge of my first fingers nail on the string. This nail is shaped by Wilko-ing/Bo Diddling[1] the guitar and it really does give a nasty 'snap' on the ukulele when it catches. I haven't trimmed or cut that nail in years. Guitar practice keeps it 'just right'
but when it catches, it stands out in a most unpleasant manner.
I practice fingerstyle exercises a lot as I love the sound the ukulele makes as I mangle classical type pieces, so I hear you loud and clear with the scratchies. Just when everything is going sweetly, KlAnG!scritch! AARGH!.
[1] Constant right hand rhythm, left hand playing short chords with a little riff thrown in. Great fun.