if you try to open service request using link from Direct link to this offering:
and you are redirect to some other page but not to correct service request
Probably the issue is with template details for the role that try to open service request via link.
go to back end then: Roles and Permissions -> here select role that has the issue example SelfService -> Top Level Tabs -> Service Catalog.
here check Search Tags:
I my case name is invalid and need to be corrected to ServiceCatalog.