case $var in $list) issue

[#!microsuxx]

i made a script in that i have a case statement with a listing separated by
| , in a var
now this errors
why

~ $ m=a\|b ; case $m in $m) echo ye ; esac
ye

works

in the script i have case .. in $shorts)
it errors says my unknown cmd printf ... pattern not found ..

~ $ echo $short
li|la|ds|fs|ac|U|S|u|s|r|i|f|c

~ $ bash m/mb.termux.pkg S bash
unknown cmd: S

has something to do with new $IFS at some point ?

greets ..