Broadband not connection

Hello can anyone help here. I have changed iOS from BT fttp to Zen fttp when I try an pppoe connection straight from the Ont to the pc it won't connect with dial up connection.
It worked with previous isp BT bit won't connect, it connects ok with the ip router but not on pppoe am I missing something out here !?.

So it works using the CP supplied router, but not when you make a direct PC to ONT connection ?

Then the likely cause is that you haven’t set up the connection details correctly in the PC.

Can you post what settings you are currently using please ?

That is, you probably need to set or change the VLAN ID (tag). And of course, the username/password has to be correct.

There is no VLAN tag on the ethernet connection from the ONT. It is dealt with internally by the ONT.

Some ISPs require the PPPoE session to carry a VLAN tag when presented to the ONT.

Sometimes that's even "VLAN 0", so that the packet can carry 802.1p QOS bits whilst remaining untagged (the same bytes carry VLAN ID and QOS bits)

I made the assumption (never a wise thing to do) that both services were Openreach FTTP which has no VLAN requirement at the router. The OP is somewhat lacking in detail, if the ZEN service is via City Fibre things could be different.

The login details are correct im gettimg an error 691.
Im don t use a vpn, it previously worked on BT four weeks ago, but won't Connect on Zen!!!.

It works on isp router, but won't pppoe dial up.

Random guess, could it be DHCP not PPP ?

Is your new Zen FTTP connection using an Openreach ONT, or Cityfibre?