Hi @Jessealfredo.

Welcome, thank you for reaching out to Sonos Community.

It's odd that you're not able to set up the surround to the new Arc.

Try network refresh first, by unplugging all Sonos devices, then rebooting the router. When the router comes back up, plug back in the Sonos devices.

After that hardwire the sub to the router or modem using an ethernet cable and add it again.

Let us know if it works. If you need help with any other information, please be sure to let us know.