The new case average peaked 25 July - 5 weeks later. Not two. But California also had data collection errors reported at the same time they "peaked". They are now showing an increase again, and added 12,290 cases on 11 August (https://www.latimes.com/projects/california-coronavirus-cases-tracking-outbreak/).
They had 3754 new cases on 18 June. 12,290 cases on 11 August - 8 weeks later!
Want to explain again how masks are working in California?
At some point, cases WILL peak in California. And then come down. That happens EVERYWHERE. Cases climb. If nothing is done, they peak and decline. With control measures, you may FLATTEN THE CURVE, but you don't stop the virus.
Suppose you are having 3,000 cases a day when you require masks. And suppose masks work to prevent transmission. Incubation time is 5 days. Almost all within 10 days. So within 2 weeks, you should see cases drop. Doesn't happen.