The crystal was not critical to our operation. It was just "nice to have" if we wanted to squeeze a more precise time base. The solution was to use V3 silicon. It was the default when buying in volume for production. The older version was just something that was left in stock. According to the follo...

Hi, I've encountered some problems trying to get the RTC clock to use an external XTAL or oscillator on an ESP32. The problem From what I've read older revisions of the silicon (before rev 3) have problems driving a XTAL. The problem is when the ESP detects the XTAL, but when it goes into deep sleep...