Most probably the usual issue with ISP provided routers blocking multicast after a short period.

If you have not already tried it, I suggest power cycling your router and see if your can get connection immediately after.

If you can get a working connection after power cycling but then the connection fails after a period, add in a hub or switch ahead of the router with just a single connection to the router and WAN.

808v6, M60, MC200, HD621, Lumagen XE, 504, SB Touch, 563, 201, 204, 208, MPMAX 221, M80, Explorer, Explorer2.