Anyone else have this kind of experience with Rotosound's compression wound strings?

[Tommy el Gato]

I recently put a set of Rotosound's "Solo Bass" strings on my fretless j-bass. They're guaged 40-100 and immediately upon stringing them up, my g-string rattles from the bridge. It could be the bridge, I'm thinking, since it is a bit flimsy and it's starting to rust apart. Still, I wanted to see if this is something that happens as a result of a faulty string or something.

[Band Dad]

I believe it was a set of Rotosounds that had a problem with an incredible fret-like buzz. Turned out to be a broken string core. Drove me up the wall trying to fix what I couldn't.

[babaseen]

I've also noticed this with the Rotosound Swing Bass set on fretless. Thought it was a buzzing on the fingerboard or bridge but finally realized it had to be the core of the string buzzing within the winding. It is only obvious when played unplugged so I hesitate to call the strings defective and still obvious when an open string is played. However when amplified the strings sound fine (not all the strings exhibit this just the D and G...and I've had other sets of Roto's do this on occasion) meaning this buzz is not part of the amplified sound. Go figure