Review on HiLetgo 2pcs ESP8266 NodeMCU CP2102 ESP-12E Development Board - Open Source Serial Module (2-Pack) by Mark Harris

From what I have done there are several batches of these boards showing the same behavior. Obviously this is related to the frequency of the crystal on the board. The first symptom is that writing to the serial monitor in the Arduino IDE produces garbage. If I connect at 115200, I can only read the output if I set the serial monitor baud rate to 74880, which is a 40:26 ratio (is the crystal running at 26MHz instead of 40MHz?). As others have noted, most things will work anyway, and you can even get a serial monitor output if you set the baud rate to about 0.65x what's actually connected. However, there doesn't seem to be a way to force a Wi-Fi connection to these boards. If anyone knows of a way to do this, I'd love to hear it. I contacted the sellers through their website. I couldn't find a way to do this on the Revain website. I did not get an answer. I've spent a few days on this and will have to return it if I don't find an answer soon. Does anyone know how to buy reliable boards? I've stumbled upon this with 2 sellers now and don't want to continue doing it through trial and error.