@musat You can change the management account password per computer very easily right in the JSS. No need to remove framework and re-enroll.
If you've confirmed that the actual local admin account password is what you expect it to be, go back to your JSS and locate the Mac. Open its details view and go to the General tab. If you have the rights to edit the record, which I imagine you do, you should see a small "Edit" button below all the information in the General section. Click that and you'll see fields for the username and password for the management account for that system. Change it there, save and go back to Casper Remote. Be sure to do a refresh in CR so its pulling down the computer data again and then try doing your Casper Remote stuff. It should work if you put in the same password as the actual account on the Mac.
I should also mention that you can do these edits in batches if you need to. From the inventory search section, locate the Macs that you think may have bad password information for them, then use the Action button from the search results. One of the options is "Edit the Management Account Information" This will let you change the db stored information for all Macs in the search at once.
All that being said, if you were using the built in Management account password change function in a policy and its not updating the database accordingly, that would indicate some issue or bug, so you might want to still open a case with JAMF to discuss it.
Make sure that when you are changing the management account password via a policy, you are using the "Management Account" policy payload and not the "Local Accounts" policy payload. If you change the password using the MA policy payload, the JSS database is automatically updated with the new password. There are a number of high security environments where a policy sets the management account to a random 32-character string (or longer) on a daily basis using that payload.
The Local Accounts policy payload only changes the password and makes no update to the database whatsoever. It's useful if the student finds out the password to a non-casper management account on the system, but if you used it to change the management account password that CasperSuite uses, you will need to go through the process that @mm2270 describes to update the account password in your database.