See explanation below.
Explanation:
The Accounts receivable payments clerk role contains the maintain customer payments duty. One of the privileges in the maintain customer payments duty is the Post customer payment journal transactions privilege.
You need to duplicate the Accounts receivable payments clerk role and duplicate the maintain customer payments duty. Remove the Post customer payment journal privilege from the new duty. Remove the original maintain customer payments duty from the new role and add the new duty to the role. Remove the Accounts receivable payments clerk role from Arnie and assign the new role to Arnie.
This solution will ensure that Arnie can do everything he could do before with the exception of adding receivable records to the customer payment journal. It will also ensure that anyone else assigned to the Accounts receivable payments clerk role can do everything they'd expect to be able to do with that role.
An alternative solution would be to deny the Post customer payment journal transactions privilege in the maintain customer payments duty. However, this solution would affect all users assigned to the Accounts receivable payments clerk role.
Reference:
https://docs.google.com/spreadsheets/d/1Ao-5w4t80LZhks9O2WFcMZUFXfFkI3uMYxDPEXp-kz0/edit#gid=0
https://www.dynamics-tips.com/system-administration/security-roles