Migrating Sharepoint on-premise systems from Cisco ACE to BIG-IP LTM

I am migrating services from our old Cisco ACE to BIG-IP LTM, using the iApp f5.microsoft_sharepoint_2010_2013.v1.2.2.

We have several sites (hub, network, projects, search, user and workspace) for 3 environments (test, pre-production, production). The ACE isn't configured for service checking for the Sharepoint sites, no probes are configured.

So far migration has been reasonable and several services that worked on the ACE work on the LTM. All sites are built with the BIG-IP passing through SSL traffic, certificates are nt loaded onto LTM.

I'm seeing all of the "search" instances marked offline due to a failed HTTPS monitor. The monitor consists of the iApp default send string:

GET / HTTP/1.1\r\nHost: searchtest.domain.com\r\nConnection: Close\r\n\r\n for searchtest

GET / HTTP/1.1\r\nHost: searchpreprod.domain.com\r\nConnection: Close\r\n\r\n for searchpreprod

GET / HTTP/1.1\r\nHost: search.domain.com\r\nConnection: Close\r\n\r\n for searchprod

The same defaults for projectstest, projectspreprod and projects work without errors.

Where do I go next to resolve the monitor errors, please?

Many thanks!

Kev