I get message "This webpage was reloaded because a problem occurred" on safari with my iPhone 7 in iOS 14 Beta 3. Even with Beta 3. Restoring phone does not work. Restored from back up. Resetted the phone. Cleared network settings. Cleared Safari. Done all the tricks.
Same problem with 3rd party browsers, too. Microsoft Edge, Chrome, Firefox, etc.
Same problem with mobile data as well as wifi.
Safari itself doesn't crash.