Running script using at command doesn't work entirely

So I did a bash script that read a file in which are directory numbers and then proceeds to run pgloader over them.

I looks like this

#create logs for pgloader
Date=`date +%Y_%m_%d`
LOGS="pgloader_logs_$Date"

touch "$LOGS"

echo "loading files from dat folder"
echo "--------------------------------"
pgloader dat/*.load 2> "$LOGS"

#Read brand numbers from input file
while IFS='' read -r line || [[ -n "$line" ]]; do
 #check if dlnr is valid
 dlnr=$line
  if [[ $dlnr == ???? ]]; then

     echo "loading files from $dlnr folder"
     echo "--------------------------------"

     pgloader $dlnr/*.load 2>> "$LOGS"
  fi
done < "$1"

exit 1

The directory where i run it looks like

0002 0005 0021 ... setUpDB.sh brandsnr

I run it using echo "./setUpDB.sh brandsnr >> someFileToGetTheOutput" | at TIME

The problem is it never runs inside the while for some reason. Is the at command not able to read files ? Because I tried to use a for loop with a number increment instead of reading from the file but it doesn't run inside it either...

The script works perfectly when I run it myself. I just need to be able to launch it overnight...