Well, if you want to sell them, go ahead; no one really cares what you do with them.
But, if you want to get them to work right again, then unplug your Alexa devices for 5-plus minutes, and while they are off, reboot your modem/router. Plug the devices back in after five minutes and your router should also be back working by then. If things are not working better now, I would say you have wireless signal issues you need to figure out and fix.