File works manually; does not work with cron; setting PATH makes it worse
You do not need the glob (*). Try the following for the photoscript2.sh script.

#! /bin/sh
find /Users/username/Pictures/Photos\ Library.photoslibrary/Masters/2019 \
    ! \( -name '.*' -o -name 2019 \) \ 
    -mtime -7 -exec cp {} /Users/username/Documents/Recently\ Added/ \;