After inspecting logs, I'm pretty sure that it shouldn't be reauthorizing every 30 seconds. The router logs show this:
Nov 11 19:43:53 ubnt pppd[5810]: peer from calling number 04:18:D6:0E:08:88 authorized Nov 11 19:43:53 ubnt pppd[5810]: Cannot determine ethernet address for proxy ARP Nov 11 19:43:53 ubnt pppd[5810]: local IP address 10.113.0.1 Nov 11 19:43:53 ubnt pppd[5810]: remote IP address 10.113.0.12 Nov 11 19:44:23 ubnt pppd[5810]: rc_ip_hostname: couldn't look up host by addr: %lX Nov 11 19:44:23 ubnt pppd[5810]: rc_send_server: no reply from RADIUS server unknown:1813 Nov 11 19:44:23 ubnt pppd[5810]: Accounting START failed for jbaca Nov 11 19:44:24 ubnt pppd[6043]: pppd 2.4.4 started by root, uid 0 Nov 11 19:44:24 ubnt pppd[6043]: Connected to 04:18:d6:0e:08:88 via interface eth1 Nov 11 19:44:24 ubnt pppd[6043]: Connect: ppp0 <--> eth1 Nov 11 19:44:26 ubnt pppd[5810]: Connection terminated: no multilink. Nov 11 19:44:26 ubnt IMI[617]: IMI-6: Interface pppoes0 [13] not present Nov 11 19:44:26 ubnt OSPF[954]: OSPF-6: Interface pppoes0 [13] not present Nov 11 19:44:26 ubnt RIB[626]: RIB-6: Interface pppoes0 [13] not present Nov 11 19:44:26 ubnt pppd[5810]: Modem hangup
so it sounds like something is going on with rc_ip_hostname possible and rc_send_server that the poe5 is not liking. Any ideas?