Nothing remarkable in the log except maybe that despite having a good RSSI, the WiFi disconnects and connects. WiFi quality is not just a function of signal strength. It is also affected by other routers using the same or nearby channels heavily and by interference from other devices using the 2.4GHz band. It would be worth trying a switch to another radio channel. I would suggest channel 1 or 6. You would need to do this in your router.