#1 In IDM 14.1 there was a bug on the View Submitted Task page - Most recent task is not getting listed by default if total no of tasks exceeds more than 1000. To work around you will have to increase the search limit to more than your tasks eg: 5000 approx and search. This is not the issue in your case.
#2 And I asked you - Is your task getting completed(doing what it supposed to do) and not showing in the VST ?
#3 Also are these tasks are submitted via IDM admin console ? or are these Explore/Co-relate tasks which you are expecting in VST ?
#4 If your tasks are E/C tasks which are expected to sync to IDM via Inbound sync - then did you check Provisioning Server notification logs for any failure related to inbound sync urls or certs expiry...etc ?
#5 AuditViewTask Miscellaneous Properties - CA Identity Manager - 12.6.8 - CA Technologies Documentation
The task persistent database records only the submit action performed on a task. The view action is not recorded because it is not submitted. To record the view action that is performed on a task, set this user-defined property to True.
Values: True, False
#6 I would suggest to open a support case, If you are not falling under above mentioned categories.