Well, after both updates I can say the wifi dropout is less but not totally gone. It was dropping out every 20 seconds or so but now every couple of minutes.
On your wifi router, try setting the DHCP lease time to 1 day.
Many Android devices have a problem with "forever" leases.
Leases are supposed to expire, DHCP was designed to work that way, and there is no downside to having lease times as short as an hour.