Yesterday I walked into a problem that the Cisco ISR 897VA was rebooted due to a power failure in the building. There was a preload update of the IOS software. The Software which was preloaded were: c800-universalk9-mz.SPA.156-2.T1.bin.
After the reboot, the router came up. but there was not a proper connection. After checking that the software failure went into an authentication failure. I supposed it should be something with the compatibility of the software on the Cisco Device and the hardware of Orange France.
The only solution, in this case, was to downgrade back to the following software version: c800-universalk9-mz.SPA.156-3.M7.bin
Perhaps Orange FR is able to solve this issue. As customers want to have their own network device instead of the live box.
Notification of the problem there was a Carrier detect, but there was no PPP authentication possibility.