Cloud storage billing doesn't make sense to me

I don't quite understand how firebase cloud storage is billed.

I have about 200gb stored in my project, and the cost for may was around 26 USD, as I expected. Today I read up on how this service was billed and found that it would be billed $0.026/GB/month, not a one time payment. This would cause me issues and I would have to look elsewhere for a storage solution, but that error is on my end so I don't mind.

However, when I check my billing these 26 USD do not follow into June. Cloud storage starts at 0 USD as all other firebase services, but I would expect that this curve, if billed for each GB each month, would follow into the consecutive months, meaning June should also start at 26 USD and then go up from there.

Can anyone help me clear out what the deal is here? Are we billed per month or are we billed per stored GB?

Thank you!

If you're not seeing charges that you expect, reach out to Firebase support so that they can take a look at your project.