I had the same problem but even after savig config after some days my instalation at the customer keep going  to factory default just on the cpe bridge side ( the client cpe 210 never lost config  ), even after changed the cpe for other claiming waranty the result was the same

I was forced to  change to a CPE510 pair and is working fine

At my office and with better signal the problem with the 210  v3 doesn't ocur, seem that  with a bad signal the software is making a factory reset instead of a reset as workaround