Hi there and welcome
Can you do the following to try to resolve this please
1. Load the plain white letter size paper in your main paper tray
2. Lift the flatbed cover on your HP Envy. Load the 5 x 7 in item face down on the flatbed glass in the lower right corner.
3. On the front panel of your printer touch the Copy button
4. Touch the Settings icon
5. Touch Resize
6. Choose Custom at 100%
7. Scroll down and touch 'Save as Defaults'
8. Touch the Black or Colour Copy option
Let me know if it now copies please