possible bash bug bringing job. to foreground

[John Larew]

Configuration Information [Automatically generated, do not change]:Machine: 
x86_64OS: linux-gnuCompiler: gccCompilation CFLAGS: -g -O2 -flto=auto 
-ffat-lto-objects -flto=auto -ffat-lto-objects -fstack-protector-strong 
-Wformat -Werror=format-security -Wall uname output: Linux 
HP-ProBook-6450b-500GB 5.15.133.1-microsoft-standard-WSL2 #1 SMP Thu Oct 5 
21:02:42 UTC 2023 x86_64 x86_64 x86_64 GNU/LinuxMachine Type: 
x86_64-pc-linux-gnu
Bash Version: 5.1Patch Level: 16Release Status: release
Description: This is an attempted portion of a larger script I am writing. All 
these attempts appear valid; none works.
 BTW, also fails on termux 0.118.0/bash v5.22.6 (HOSTTYPE=aarch64, 
MACHTYPE=aarch64-unknown-linux-android)
Repeat-By:  1: (sleep 15s; set -m; fg %%; exit ) & 2: (sleep 15s; set -m; fg 
%+; exit ) & 
Fix: (sleep 15s; set -m; kill $PPID) &     Not a preferred solution; I prefer a 
smaller hammer.