[Godzil]

the command line contain some contradictions:

-a mean "automatic"
but
-r mean "interactive"

fsck.vfat -atVw

is enought

See the fsck.vfat help:

usage: fsck.vfat [-aAflrtvVwy] [-d path -d ...] [-u path -u ...]
               device
  -a       automatically repair the file system
  -A       toggle Atari file system format
  -d path  drop that file
  -f       salvage unused chains to files
  -l       list path names
  -n       no-op, check non-interactively without changing
  -p       same as -a, for compat with other *fsck
  -r       interactively repair the file system
  -t       test for bad clusters
  -u path  try to undelete that (non-directory) file
  -v       verbose mode
  -V       perform a verification pass
  -w       write changes to disk immediately
  -y       same as -a, for compat with other *fsck