I have an Archer AX50 that performed with no problems for around two years. But for the past month or so, whenever a phone or laptop first connects to either the 2.4 or 5 GHz network, the IP address that gets assigned has only around a 50% chance of being functional for connecting to the internet. The router address is 192.168.0.1, and the functional addresses are always 192.168.0.nnn. But often (around half the time) the addresses that get assigned are of the form 192.168.100.nnn, and the router address shows up on the device as 192.168.100.1. When the assigned address has 100 in the third position, rather than 0, there is no internet connection. On any of the three computers in the house (macOS), if I repeatedly click Renew DHCP in the Network Preferences Advanced window, eventually it will get assigned a proper address (with 0 rather than 100 in the third position) after 1 - 5 tries. On our iPhones, there is no Renew DHCP button. Turning WiFi on/off repeatedly sometimes solves this, as does switching between the 2.4 and 5 GHz network. Any ideas about why this is suddenly happening, and how I can fix this? Rebooting the router solves it but only temporarily. This may be a coincidence, but the problem began after the router and cable modem were all disconnected from power for a few days. Thanks in advance for any suggestions.