To recreate: 1. Turn on the SCO module and enable 'OPACAllowUserToChangeBranch'. 2. Place a hold for a user and then login to the SCO module 3. Under the hold tab try to change the pick up location for an item 4. Notice you are redirected to '/cgi-bin/koha/opac-modrequest.pl' and forced to log in again. 5. Re login to the SCO module and notice the pickup location for thta branch was not updated.
The form for this comes from 'holds-table.inc' and it looks like it may have never been intended to work with the SCO module?