My home internet usage just spike the last 3 days about 200 G per day

My home internet normally range about 400 to 600 G per month.  For some reason my May 2025 usage just spike about 200 G per day this week and it is hitting the 1.2T data limit for the month.  Do you know what would happen to this kind of spike?  

I just changed my wifi network password recently to ensure there are not other users using my data.