I had many contents stored in my Flow.

1

I had many contents stored in my Flow.
Flow was synchronized by my PC and Android browser.
But, At a day I logged out my Android account and created a new one there.
Then I logged out the new account and logged in the first account.
When I logged in by that, I checked my Flow and I saw all contents was removed.
They are removed from both my Android account and my PC account. Why did this happen and how can
I restore them?

2

I have no idea what flow is. Sorry.