F5 mssql health monitor failing

Have you done more investigations ? Tcpdump to see if the response is really wrong also I don't see what is your receive string  string ? Maybe configure the monitor with server name  "icscwsql1"?

Outside of that if it doesn't work be on the latest 17.15.3 and if needed open a support case and you can make your own monitor https://my.f5.com/manage/s/article/K71282813  / https://my.f5.com/s/article/K000149155