Plucking sound to my Ukulele?? Bad strings or unknown mystery?

WOW !!!!

If they are too stiff, most likely you have tuned the ukulele a whole octave too high. This may cause severe damage to the bridge area. Most ukulele are tuned to GCEA (the A string is closest to the floor).

Try this:

Put an electronic tuner on your ukulele and strike the "A" string -- lowest string to the floor when a right handed ukulele player is holding the uke. (or play an A note on a piano) Look and listen to see if the ukulele is tuned to an "A" note. If it is not an "A" note, loosen the string until it plays an "A". Then tune the rest of the strings.

If the strings are still too tight, loosen the string a whole octave down until the string plays an "A" note again. Go all the way from A to G to F to E to D to C to B to A.

Check the string tension. Is it closer to normal? If so, lower the remaining three strings a whole octave as well.

E string: E to D to C to B to A to G to F to E

C string: C to B to A to G to F to E to D to C

G string: G to F to E to D to C to B to A to G

If the strings are now "flopping all over the place" then you have a different problem and you may need new strings.