WAN PPPoE DSL change to WAN DHCP cable insanity

[nerdy]

Hi everyone.  I ran into a very serious problem migrating from my dsl service to cable internet.  the wan interface would not allow the change from pppoe to pain dhcp.  the error it would give is that the interface had to be reassigned.

I am using 2.1 and have a lagg interface with vlan trunking and branch to branch and client open vpn connections.  with this,  the router would take forever to boot up, still looking for or a wan connection, but the wan would also be stuck on pppoe, even when I reassigned the wan interface to DHCP.  in the end, I had to factory default and load in the backup configuration bit by bit while losing a whole day of connectivity.

Has anyone experienced this problem? will there be a seamless way to do this from the gui?