I have noticed this behavior if you have created IDM roles before enabling the EnableSMRBAC.
Can you create new role now and check whether it is reflecting or not?
Additionally, you can verify SM database table for IM related stuff.
i.e. IMSROLE6 , IMSTASK6 and IMSROLETASK6 Role table has the entries related to your IDM task.
Check the following image here "IMSROLE6 " and "IMSTASK6" has entries but Role and TAsk mapping table "IMSROLETASK6 " were missing those entries.
Either you create these missing entry manually or recreate those roles and task again in IM console.