Hiya Si.
Short scale bass strings are under less tension than full-scale counterparts, so the strings are more 'floppy' This affects the attack and response.
I've got the same Gretsch (Junior Jet 2), and the difference in string tension between this and one of the full-scale basses is very noticeable.
As others have said, try lowering the PUPs, or giving it less of 'the beans'!
Good luck with your gig! 👍