Who I have the same questioned this topic

On June 24 at 12:06 pm, when I was at home and on wifi, there was a data usage of .59483 GB on my iPhone 7. Later that day, when I was driving for Uber and streaming Pandora, the data usage was .74552 GB. Compare this to June 9 when I used data in a similar way, but only used .11801 GB. What is the reason for this extreme jump in data usage and also for using data when I was actually not using data? I do have wifi assist turned off. Because of this spike, I have been charged for going over my usage when I shouldn't have gone over.