After the last Emacs upgrade to 26.1, the M-s key bind from paredit-mode is replaced by `Next element matching (regexp)` command in the slime repl buffer. Sorry for the silly question, but how to get M-s mapped to paredit-splice-sexp again? In a lisp file buffer it is working as expected.
Best,
-- Alexandre Rademaker http://arademaker.github.io