Have you rebooted the printer to see if anything changes?
The first thing I advise is to give the printer a static IP address. This means it will not change. Letting DHCP on your router assign its address can be problematic, because it's not guaranteed to stay the same. The router then has to be told what the static address is, so it will be reserved for the printer. The router supplier or manufacturer can help you with this.
After you've done this, see if the WiFi connection is more reliable.
