You can safely ignore .fuse_hiddenXXXX files. It means a file was
deleted but there is at least one software which is still using it, so
it can't be removed permanently.

It will be done automatically when the relevant software stops using
the file or exists. Such files are always gone after umount/reboot.
This is how Linux and any Unix works but only FUSE exposes these files
to the user.

These are likely files that were meant to be deleted but are somehow still in use.^UBF