The "Selected Index" attribute in select dropdown element in the form no longer works as expected once catalog is upgraded from 14.1 to 17.1 and applied 17.1 rollup2 patch
ITSM service catalog 17.1 with rollup2 patch applied , and the versions afterwards .
Normally the users do not purposely specify "Page Size" attribute for select dropdown . With default value ( i.e. no any value specified in "Page Size" ) , on 14.1 , when form is loaded , it loads ALL the data to pre-populate the select dropdown list at the very beginning . Therefore , whatever value specified in "Selected Index" will work as soon as it is in the dropdown list.
However , with 17.1 ( specifically after 17.1 rollup2 patch and the versions afterwards ) , our dev made continuous effort to improve/enhance the overall performance relating to the forms . With default value in "Page Size" attribute ( i.e. no any value explicitly specified in "Page Size" ) , it loads/pre-populates only 7 entries in the list first at the time that the form is just loaded at the very beginning . if "Selected Index" attribute value is greater than 7 and the "Page Size" attribute value is empty , it will not be work in 17.1 because the "Selected Index" value is less than the default "Page Size" value 7 here .
From 17.1 rollup2 and the versions afterwards , when specifying "Selected Index" value for select dropdown , it has to combine with specifying "Page Size" value . For example , if you want to specify "Selected Index" value as 72 , you have to also specify "Page Size" value and set "Page Size" value be greater than or equal to "Selected Index" value 72 here .