Why is Google Drive creating multiple folders with the same name?

This issue is a known thing that can happen and (sadly) there’s not much that can be done about it.

Google Drive doesn’t enforce unique folder names, which means you can have lots of paths with identical names.

UpdraftPlus when it goes to backup will try to look up the folder name in your Google Drive, if this fails it will try again. If it fails again then it will create a new one in order to carry on with the backup. This is better than no backup i.e. the other option being we failed to look up the folder so lets not do a backup.

The folder lookup could be caused by a temporary network issue or something similar.

You could manually move all of the backups into one of the folders and then delete the other folders.