They were probably a different guage than your originals.
Try not to use heavy strings on short scales, they don't work well. 45,65,80,100 is the heaviest I would go on a short scale.
Most shortys come stock with 45,60,75,95 which is actually better for the neck. Except for LaBella hofner Beatle Bass Strings, which are made the old way in which case the core is exposed and it is the core that is wound around the tuning posts. If you use these DO NOT CUT THEM. They fit perfect with no cutting needed. If you have a Mustang type bass use Medium scale strings or cut a set of longs. Shorts wont fit a Stang or Musicmaster. I hope this helps.
P.S. The new strings you tryed are probably ok you just need to intonate the bridge some.