Mikrotik "LNS" PPPeO over L2TP

We've two MikroTik CCR 1036 as LNS receiving ppp traffic from broadband aggregation group over l2tp tunnel. this solution is known as LNS and working without issue in Cisco, but there are some issues with our mikrotik setup and it's not getting pppoe frames. Note that mikrotik support LNS surely from 6.35 and we've done this setup earlier but configuration is lost. Only Senior Network Engineers (with LNS experience especially on mikrotik or cisco ) bid please.