Hello,
Based on your description, it is true that you may encounter network connection issues or file system errors when copying large folders.
You can first use the ping command to test whether the network connection between server A and server B is stable. And then you can check to see if the target folder on Server B has enough disk space to accommodate the entire folder.
Finally, it is recommended that you try using the Robocopy command line utility to copy the entire folder.
Thanks,
Shujun