Describe the bug

A problem has been identified with user favorites being removed after portlet definitions are deleted.

After a portlet is deleted, if a user had that portlet favorited, the section for that portlet in the favorites section of the user's layout is not deleted, but instead appears similar to:
{
"_objectType": "portlet",
"url": "/uPortal/api/v4-3/portlet/DLMStaticMissingChannel.html",
"iconUrl": "/uPortal/media/skins/icons/mobile/default.png",
"ID": "n241",
"chanID": "-1",
"description": "",
"fname": "DLMStaticMissingChannel",
"locale": "en_US",
"name": "Missing channel",
"timeout": "20000",
"title": "Missing channel",
"typeID": "-1",
...
}

This doesn't initially affect users, as their favorites continue to display. But if they favorite another portlet, then when they log out and back in, the new favorite doesn't appear, and sometimes other portlets have also disappeared. Likewise, if the user removes a favorite, sometimes other portlets have also disappeared. Specifically, in both cases, the portlets that appeared after the deleted portlet ("Missing Channel") no longer appear (they have been removed).

Steps to reproduce

1. login as any user
2. favorite four portlets (note the name of the second portlet favorited)
3. logout
4. login as an admin user
5. go to Portlet Admin portlet
6. delete the portlet that was the second favorited previously
7. logout
8. login as same user from step 1
9. view the Favorites portlet (you'll see that the second portlet favorited is no longer listed but other three remain)
10. favorite another portlet
11. view the Favorites portlet (you'll see the four portlets listed)
12. logout and then log back in
13. view the Favorites portlet (you'll see that the last three portlets previously seen are no longer listed)

Repeat steps 1-9 with a different user, then follow these steps:
10. unfavorite the first portlet listed in Favorites portlet
11. view the Favorites portlet (you'll see the two remaining portlets listed)
12. logout and then back in
13. view the Favorites portlet (you'll see that the two portlets are no longer listed)

Expected behavior

After a portlet has been deleted, it should no longer appear as a favorite in the Favorites portlet for users that had favorited the portlet. This works fine. When those users subsequently modify their favorites (either by adding new ones or removing existing), no additional portlets should disappear automatically.

Stacktrace

No response

uPortal version

uPortal 5.16.1

OS

No response

Browser

No response