First, I would go to packetlosstest.com on your deck in desktop mode and see if it shows any issues. They have some game presets you can pick to hopefully test network connections similar to what you’re having issues with.

Once you have a baseline test of how your internet is performing, some basic things to try to improve it are:

• Reboot deck and wifi router.
• Switch between 2.4Ghz and 5Ghz
• Try playing closer to the router and see if the lag goes away.
• Disable the wifi power management setting on the deck

Even if nothing has changed with the Deck and router, it’s possible another device in the house is causing interference, especially on 2.4Ghz networks. If the problem is something else causing interference, it can be really confusing to troubleshoot from the network side of things because the problems will be very intermittent.