Editing a Program Increment when you do not belong to the saved portfolio allows you to change the portfolio

Issue Summary

When editing a Program Increment, initially the screen will lock the portfolio field if you do not belong to the saved portfolio. If you attempt to save an edit, you get a "select a portfolio" error, the screen reloads and it unlocks the Portfolio field, displaying all (if any) portfolios you have access to. You can then proceed to assign a new portfolio and save changes successfully. This causes several issues: You can't re-select the previous Portfolio since the list only populates with portfolio you have access to. If you don't have access to any portfolio, you won't be able to save changes to a PI at all, despite having permission to edit PIs. Users may also unknowingly change the Capability status and various reports by changing the assigned portfolio to a PI. This also requires more hands on user management as each user that's not a super admin needs to be added to each portfolio before they should be allowed to edit PIs.
This is reproducible on Data Center: Yes

Steps to Reproduce

1. Create a Program Increment per user documentation Create program increments
2. Log in as a user that is not a super admin that is not part of the Portfolio used to create the Program Increment but does belong to other Portfolios and permission to edit Program Increments.
3. Open the program increment created in step 1. You should see that the Portfolio field is locked from editing. Edit any other field and attempt to save the change.

Expected Results

Being able to save the Program Increment while maintaining the original portfolio but having the portfolio field remain locked, possibly with a warning about why the field is locked.

Actual Results

A "select a portfolio" error is displayed and the save is not successful, but the program increment screen then reloads and allows the portfolio field to be changed.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available