From a second, unrelated bash shell:
$ kill -SIGSTOP 16690
- $ kill -SIGCONT 16990
+ $ kill -SIGCONT 16690
- <at this point 16990 exits and causes 16644 to exit too>
+ <at this point 16690 exits and causes 16644 to exit too>
This happens because bash can observe both signals and choose how it
responds to them.