In Feb 13, 2013 i wrote about the problem of connecting the router as a PPPoE client (log attached): Problem with PPPoE Connection.
I'm sure if you search you can find more similar topics. With a similar request addressed another person: Feature Request: PPPoE #of PPP LCP ConfReqs before PADT sent.
There was no answer.
If are unable to add this item to configure, may be possible to simply increase the number of requests to 5?