I've had that behavior when adding a replacement bowler to a team, and I did just that tonight to duplicate. BLS 2017 PRO 29.05.05 and previous versions.
Since I'm not on an AS version, I do all my substitute additions in the scores entry screen and have not run into this issue.
In my duplication test, however, I couldn't get it to repeat. Once I had one instance where Kerry's results were duplicated, it didn't happen again, whether adding the same or different substitute to the same or another random team. I even advanced a week to see if something resetting things affected it there...no repeat. I even restarted Windows 7 to see if, after a restart, it would recur...it didn't. Kerry's workaround does suffice, and so does changing to a different team (PageUp/Down) and then returning to modify the lineup.
So, I don't know when/if I'll encounter this issue again, but I can concur that I have observed it multiple times.
Always check, download, and install the most recent update of your software to ensure that issues may have been corrected.