I have the RT-AC66R running ASUS f/w ver: 188.8.131.52.382_52287. I've forgotten all about alternative f/w for this router. What is recommended to try or simply upgrade the router at this point? The LAN seems fine but WiFi seems to vary at times. Might be the device I'm testing from (shouldn't be, ex: Samsung 21 Ultra - 6E compatible) or WiFi interference from being in a townhome. Just looking for the best f/w options.