Update README.md

Author: flash62au

README.md

@@ -78,6 +78,8 @@ While the basic form is simple, the design is flexible and you can add several a
 
     *Note: any ESP32 will work but the pinouts may need to be adjusted, and a separate LiPo charger may be required*
 
+    *WARNING:* I have reports of some of the versions of this board with the USB-C connectors having problems with the WiFi.  Some are clearly fine, but others are not.  I am still investigating this, but I would recommend avoiding the USB-C version for now.
+
 2. 3x4 Keypad  ([Example](https://www.jaycar.com.au/12-key-numeric-keypad/p/SP0770?pos=2&queryId=20aedf107668ad42c6fe1f8b7f7a9ca7)) 
 
     *Note: Alternately a 4x4 keypad can also be used (see optional components below)*