What IPv6 setting should I have & what kind of internet does Xfinity provide (PPPoE, static, etc.)?

Recently I noticed my internet ping being unstable while gaming. Thought it was my router or modem but turns out I had IPv6 off and once I turned it on, the lag got fix and my download speeds are now stable. I just want to know what the actual setting should be for my Asus RC-3200 AC router. For the connection type, I have options for disable, native, static IPv6, Passthrough, Flet's, and Tunnels. Also, what is WAN and what option should that be on? I have options for automatic, static, PPPoE, PPPtP, or LT2P.

Thanks!