I have had 3 Flash drives connected at the same time. That is not THE issue.
Only if one behaves as a Device, is the issue.
Connect to Folder makes a drive appear to be a device (very useful for devices that Calibre can't identify properly, but appear as a drive to the OS)
The status line at the bottom usually indicates: xyz connected if that happens
(and the 'Location Bar', which is device type sensitive, appears. Preference:Toolbars: ...when connected)
and the OnDevice column shows. these are all clues
Normally
Connect to Folder expires when you close Calibre (or eject the folder device)
BUT
there is a tweak:
Code:
#: Specify a folder calibre should connect to at startup
to force a reattach
Some USER tweaks were done a looooong time ago and forgotten about. Things changed and now the tweak is producing unexpected results.
(I am a Technician, not an Author. We just see different things)