LAG！！！！

I experienced no packet loss from entering a match until landing on the ground. Upon landing, the server ping began fluctuating wildly between 150 and 900. I'm located in New Zealand, connected to the ap-southeast-1 server via Wi-Fi. This behaviour was entirely absent a week prior, emerging during the final week of Season 26.

I've checked my WiFi, verified game integrity, reinstalled the game, and examined every possible setting – nothing has worked.

Any suggestions?
I'm confident my WiFi is functioning perfectly.