TDE Backup Cert Cannot write into file error

Currently running Microsoft SQL Server 2019 (RTM-CU17) and attempting to implement TDE.
SQL Server service is running under a domain account. That service account and NT Service\MSSQLSERVER are members of the local administrators group..

After creating a MASTER Key and CERTIFICATE, ( CREATE CERTIFICATE [SERVER_A_MSSQLSERVER_TDE_Cert] WITH SUBJECT = 'SERVER_A MSSQLSERVER TDE Certificate' )
I attempt to backup those with the following commands:
BACKUP SERVICE MASTER KEY TO FILE = 'g:\MSSQL\backups\SERVER_A_SQL_Keys\SERVER_A_MSSQLSERVER_TDE_SvcMaster_Key.bak' ENCRYPTION BY PASSWORD = 'ThisIsStrongP@ssword#1'

BACKUP MASTER KEY TO FILE = 'g:\MSSQL\backups\SERVER_A_SQL_Keys\SERVER_A_MSSQLSERVER_TDE_Master_Key.bak' ENCRYPTION BY Password = 'ThisIsStrongP@ssword#2'

BACKUP Certificate [SERVER_A_MSSQLSERVER_TDE_Cert]
TO FILE = 'g:\MSSQL\backups\SERVER_A_SQL_Keys\SERVER_A_MSSQLSERVER_TDE_Cert.bak'
WITH Private KEY (FILE = 'g:\MSSQL\backups\SERVER_A_SQL_Keys\SERVER_A_MSSQLSERVER_TDE_Master_Key.bak',
ENCRYPTION BY Password = 'ThisIsStrongP@ssword#3' );

The backup of the service master key and the master key run successfully, however the backup of the certificate fails with the following error: Msg 15240, Level 16, State 1, Line 1
Cannot write into file 'g:\MSSQL\backups\SERVER_A_SQL_Keys\SERVER_A_MSSQLSERVER_TDE_Master_Key.bak'. Verify that you have write permissions, that the file path is valid, and that the file does not already exist.

I realize SQL will modify the ACL of those files after they are created, but I have verified the necessary accounts are in the local administrators group...

What am I missing ?

The SQL Server service account probably does not have write permissions to the SERVER_A_SQL_Keys folder. I suspect the easiest way to get the permissions correct is to create the folder with xp_create_subdir.

@Kodyaz, Thanks for the quick reply... but if the service account did not have write permissions to the folder, it would not have been able to save the backups of the service master key and master key ...

Just in case I verified it has full control of that directory....

I'm at a loss !