Before buying an Ethernet adapter for an Era 100, test whether the problem is one speaker’s connection or only appears when you group rooms. The fix and the cost are different.
Test the room before pricing the cable
Play the same source on the Era 100 alone, then add the room it usually plays with. Repeat from the same location. If the speaker plays reliably alone but drops out only when grouped, note which room drops first rather than ordering an adapter for the room where you happen to hear the problem.
Budget for the supported connection
Sonos documents wired options and model exceptions. Check the adapter that supports Ethernet for the exact speaker and add the cable route to the price. Do not assume wiring this speaker will create a dedicated wireless network for the rest. If you can borrow the correct adapter, compare a wired and wireless session with the same rooms and source. Keep the purchase only if it fixes the failure you can reproduce.
See the manufacturer’s guidance for current requirements. Related: sonos trueplay phone compatibility before buying.
