Problem with session management iRule

Hello everybody

I would like to inquire into this problem we're experiencing with our Big-IP. We have this iRule, which does session management, attached to several of our virtual servers. This iRule performed flawlessly while we were using version 12 of the Big-IP but is corrupting our Logon APM logo since we upgraded to version 13. I list the iRule:

if { ( [HTTP::cookie exists MRHSession] ) and not ( [ACCESS::session exists -state_allow [HTTP::cookie value MRHSession]] ) } {

        if { ( [HTTP::uri] ne [ACCESS::session data get session.server.landinguri] ) and not ( [ACCESS::session data get session.server.landinguri] eq "" ) } {

            HTTP::redirect [ACCESS::session data get session.server.landinguri]

        }      

    }

}

when ACCESS_SESSION_STARTED {

    set landinguri [ACCESS::session data get session.server.landinguri]

    switch -glob $landinguri {

        "/owa/plt1.ashx?*" -

        "/owa/sessiondata.ashx?appcacheclient=1*" -

        "/owa/userspecificresourceinjector.ashx?*&appcacheclient=1*" -

        "/owa/manifests/appCacheManifestHandler.ashx?owamanifest=1" {

            ACCESS::respond 403 -version "1.1" noserver "Connection" "Close"

            ACCESS::session remove

            return

        }

    }

}

This is how the Logon page of the APM item displays when the iRule is active on the listener [a link to the image]

https://imgur.com/a/tfMSgjG?

When I remove the iRule, the logo is displayed correctly just as in version 12 of the Big-IP

We believe this is related to some changes in the functionality of the Big-IP.

Does anyone have any idea as to what might have gone wrong?

Regards,

George