You need to log and read full log for errors. Then you see why it happens. If it is communication errors, e.g. "ok" being received as "o" or "k" which happens for some more frequent then it should you should try different baud rates or usb cables. 115200 instead of 250000 and vice versa.
If your buffer is smaller then you have set in connection data you will also get such errors regularly.
