@leonknook The router you were using may have been stepping on the local wireless channel. Switching to another channel and lowering the antennae power might have been enough.
In access point mode the duet will put out a relatively weak signal compared to a full wifi router. It shouldn't cause any issues. It can be difficult for the Duet to pick up a wireless signal from a router outside the same room as it, so I think you'll be alright.