Allowed Memory Size Error FTP Transfer

New FreePBX 60 appliance with FreePBX 17 restored from an old FreePBX 16 appliance.

The backup job completes (I can download the local file), however it fails to transfer to the FTP server with the following error:

Allowed memory size of 536870912 bytes exhausted (tried to allocate 588193320 bytes) in file /var/www/html/admin/modules/filestore/drivers/FTP/PhpseclibV3SftpAdapter.php on line 47

This did not happen with the previous appliance. Changing the values in PHP.ini did not solve the issue. Where is this FTP PHP file obtaining that file size limit? I opened that file in the terminal and there was nothing on line 47 to suggest a size limit.

Here is the full error text at the end of the backup job when it goes to transfer via FTP:

Saving to selected Filestore locations
Whoops\Exception\ErrorException: Allowed memory size of 536870912 bytes exhausted (tried to allocate 588193320 bytes) in file /var/www/html/admin/modules/filestore/drivers/FTP/PhpseclibV3SftpAdapter.php on line 47
Stack trace:

  1. Whoops\Exception\ErrorException->() /var/www/html/admin/modules/filestore/drivers/FTP/PhpseclibV3SftpAdapter.php:47
  2. Whoops\Run->handleError() /var/www/html/admin/libraries/Composer/vendor/filp/whoops/src/Whoops/Run.php:510
  3. Whoops\Run->handleShutdown() [internal]:0
    PHP Fatal error: Allowed memory size of 536870912 bytes exhausted (tried to allocate 588193320 bytes) in /var/www/html/admin/modules/filestore/drivers/FTP/PhpseclibV3SftpAdapter.php on line 47