My suggestion is to rename your Calibre configuration folder, then start Calibre, which will recreate it with 'factory settings'
Note: Underscores are SUBSTITUTED when a OS meaningful character is encountered in the filename (like / or wildcards)
could you have // (escaped /) in a template? a single /, is make a folder level

Preference (Add/Send) settings only affect First use
You need to make REVISIONS down im Preferences PLugins
OR (simpler)
With the device connected: Right click the Device Icon: Configure