Find command works in terminal but not in automatic shell script

Question

I am writing a script that automatically copies sqlite files from my computer to a USB stick whenever the stick is inserted. It makes a new directory on the USB that takes the hostname of the computer, as I will be downloading from multiple computers.

The script is as follows:

#!/bin/bash
# Set the source folder to download from
src_dir="/home/atlas/atlas/runs/server"
Define hostname
usb_hostname=$(cat /etc/hostname)
Find USB path
usb_path=$(find /media/atlas/*/ -maxdepth 0 -type d -print -quit)
echo "USB path = $usb_path"
Set the destination
dest_dir=$usb_path$usb_hostname
Mount the USB device
sudo mount -t vfat /dev/sd?1 dest_dir
Create a directory on the USB stick
sudo mkdir -p $dest_dir
Copy the files with 'sqlite' in the extension from the source folder to the destination folder
find $src_dir -type f -iname "sqlite" -exec cp {} $dest_dir ;
Unmount the USB device
sudo umount dest_dir

The script works perfectly when I run it in terminal, however when it runs on insertion it fails on the 'find' command (line 'usb_path ='), where it returns 'No such file or directory'.

Things I have tried:

• Setting 'sleep 5' at the start of the script to allow time to mount; I've extended the time of this too with no change
• Checking permissions for the script to access the /media/atlas/ directory
• There are no errors in the syslog file
• 'atlas' is my user; if I change this to $(whoami) the script changes the path to /media/root/ and also cannot find any directory
• The USB device is mounted correctly (as I said, the script works fine from terminal)
• I've checked and the script does recognise /media/atlas, it just doesn't recognise any sub-directories

I'm at my wits end here. I can see that the problem is that when automatically run, the shell script can't find any directories within /media/atlas/ but I have no idea why. Any suggestions would be very much appreciated.