Hi @jamby75, some things you can try is to update both your router firmware to the latest, so as your printer too.
1. For the WiFi settings in the router, what settings do you set, e.g. wpa2 , with AES / TKIP? another possible to check is to change to a less congested channel if using 2.4Ghz. Do note that 5Ghz range is limited, but lesser interference.
2. else if possible, use LAN cable to connect directly to the router
3. for static ip, is there any other devices configured? one way is to connect to your network, either by wired or wireless, execute ipconfig in command prompt (windows) or ifconfig in terminal for mac. e.g