On my new Moto G5 plus, I started getting a [DF-DFERH-01] error when searching on Google Play Store. A quick search showed this was a common problem among different phones. I traced the problem to the latest upgrade of Google Play Store version from 7.0.17 to 8.5.39. The fix is to disable auto-update and uninstall Google Play Store updates back to factory version.
To turn auto-updates on or off, follow these steps:
Open Google Play Store.
Tap the hamburger icon (three horizontal lines) on the top-left.
Tap Auto-update apps.
To disable automatic app updates, select Do not auto-update apps.
To uninstall updates for Google Play Store, go to Settings > Apps and notifications > Google Play Store > '...' menu > Uninstall Updates
(instructions may vary slightly between versions)