I recieved two new raspberry pi 3B+ from SainSmart and they are both significantly slower than the Pi3B and Pi3b+ that they replaced. First noticed it when it took longer to boot and all functions are laggy. These new Pi3b+ have a different pcb layout than my original one and are not connecting to the wifi. All it shows is no wireless interfaces found. These Pi's were on sale for $20-$30 did I get shipped duds or am I missing something?