For further reference: I was also having issues with images not loading on Android (I’m also using the Download Image node). All the images I was trying to download were from wikimedia (https).
Unchecking “Verify Peer” solved the problem.
Also, I don’t know if this is necessary, but I also added an extra permission on Project Settings -> Platforms / Android: android.permission.INTERNET. Might be needed when you publish the app.