I'm having the same issue with the same exact error. The password policies match with GPO. The service account is set as owner of the OU. For testing the service account is set as domain admin. The forest is 2019. It creates the account but does not apply the password. I've tested every setting I can think. I'm beginning to think it may be a bug.
INFO , newuser.NewUserUtils, {GF6Au} created user entry: cn=asdfgg asdfgg,OU=Guest,OU=Users,OU=User Accounts,DC=testdomain,DC=com [10.0.0.199]
2024-06-25T01:09:16Z, ERROR, newuser.NewUserServlet, {GF6Au} error during user creation: 5049 ERROR_NEW_USER_FAILURE (unexpected ldap error setting user password for new user entry: javax.naming.directory.InvalidAttributeValueException: [LDAP: error code 19 - 0000052D: AtrErr: DSID-03191072, #1: [10.0.0.199]
0: 0000052D: DSID-03191072, problem 1005 (CONSTRAINT_ATT_TYPE), data 0, Att 9005a (unicodePwd)
])
2024-06-25T01:09:16Z, ERROR, newuser.NewUserServlet, {GF6Au} 5049 ERROR_NEW_USER_FAILURE (unexpected ldap error setting user password for new user entry: javax.naming.directory.InvalidAttributeValueException: [LDAP: error code 19 - 0000052D: AtrErr: DSID-03191072, #1: [10.0.0.199]
0: 0000052D: DSID-03191072, problem 1005 (CONSTRAINT_ATT_TYPE), data 0, Att 9005a (unicodePwd)
])
2024-06-25T01:09:16Z, ERROR, http.PwmResponse, {GF6Au} 5049 ERROR_NEW_USER_FAILURE (unexpected ldap error setting user password for new user entry: javax.naming.directory.InvalidAttributeValueException: [LDAP: error code 19 - 0000052D: AtrErr: DSID-03191072, #1: [10.0.0.199]
0: 0000052D: DSID-03191072, problem 1005 (CONSTRAINT_ATT_TYPE), data 0, Att 9005a (unicodePwd)