Authentication error on 20% of pppoe clients after mass power cut

RouterOS The User Manager
1

We have a CCR1016-12G as pppoe server and for authentication we have a second CCR1016.12G running usermanager.
We have about 190 pppoe clients that authenticate by a username only (no password required)

This morning we had a power cut that brought 95% of our client down. Our CCR’s and AP’s etc all run on batteries so were not affected.
After power came back on all clients tried to connect again but many failed with “authentication failed”.

Only by disabling and enabling again in the user manager the clients are accepted by the pppoe server again…

CCR all run ROS 6.34.2 with upgraded firmware.

Any clues?

2

We found out that the units denied the authentication still had ‘active’ connections in the usermanager.
By setting ‘shared users’ in the “constraint” section of user manager from 1 to 2 the client connected.
But by now we have a second ‘active’ connection. This is no good. Another power cut and we need 3 connections etc.?

Should the ‘active’ connections (in usermanager) not cease when the actual client physically disconnects?