When I used my Samsung S8 in a DayDream headset, it crashed continuously. I was constantly getting the message “Insert phone into daydream headset”. After trying charging, reinstall and swearing, I found the answer.
On the Samsungs, turn on “Performance Mode” before starting up Daydream. I also found some tips with aluminiumfoil to block the NFC, but that doesn’t really seem to be required if in Performance Mode. Problem is though, that the battery goes even faster now…