There are a couple of possible issues I can think of
1) Make sure you are using the same project portfolio table in BOTH the custom list view AND the slush bucket
for example: if I customize the pm_m2m_portfolio_project table, but use pm_project_portfolio in the slush bucket , it will appear to not be working because the custom view is on the wrong table
also make sure you really want to use the cross reference (m2m) table and not the project table
2) Less likely, but there could be a data policy or a security restraint or some other security setting allow uses to not see the other data values. You can validate by impersonating another use that should be able to view them and pull up the same personalized sys view you created as the admin
if neither of these appear to be the issue, please post your view from
https://yourinstance/pm_m2m_portfolio_project_list.do?sysparm_view=sys_ref_list
as well as the slushbucket table view (in this case they DO NOT match), therefore it will appear not to work
but if they DO match, and there are no security/AC: constraints, then the display should work, like below
