Strange F5 behaviour after adding an iRule

Hi all

After some further digging on a blank Loadbalancer i have found the following.

Adding this iRule then backing up and restoring an archive will mean the iRule will dissapear.

when HTTP_REQUEST {
if { [HTTP::host] contains "reports."} {
}
else {HTTP::redirect https://[HTTP::host][HTTP::uri] }
}

However the following version will still appear after backing up and restoring.

when HTTP_REQUEST {
if { [HTTP::host] contains "reports."} {
HTTP::redirect https://[HTTP::host][HTTP::uri] 
}
else {}
}

If anyone has any ideas why this happens i would be very interested in hearing as i am pulling my hair out trying to work out why.

Thanks

Simon