How can I recover missing Notes on my iPhone 12 Pro?

This morning I clicked on accepting the agreement with related notes. Immediately, absolutely all the notes disappeared, there are about 300 of them. After 30 minutes, all the notes were restored, but only 1200 of the 1,500 items were preserved. They rolled back five months. Moreover, yesterday's other notes have been restored. Therefore, it is not related to iCloud. I see the same thing through the iCloud web app as on my phone. I really need these 500 items!

[Re-Titled by Moderator]