Mikrotik PPPOE and LANCOM

I’ve a new problem.

I use mikrotik with PPPOE server. One user would use a lancom router, but this router can not connect the PPPOE Server.

The Lancom ask the server, get connection an after 10sec he disconnect. The Mikrotik say “connection terminated” an the LANCOM get a timeout. Some other router, like Linksys or AVM works fine.

What can be the problem?

Thanks for answers