Your mention of OneDrive made me remember that pass creates a cleartext copy of your password file, while you are editing it. pass will try to create the file

Your mention of OneDrive made me remember that pass creates a cleartext copy of your password file, while you are editing it. pass will try to create the file in /dev/shm but if this fails it will use $TMPDIR. If you're on a platform without /dev/shm you'll want to use some other equivalent such as a small ramdisk, or at the very least be sure your $TMPDIR is not synced into the cloud.