Reactjs – Notion API Unsaved transactions: Unrecognized error

Please help, I’m new to Notion…

I have a server.js file that make a request to notion API to create the row in notion DB. Yesterday it was working correctly, the row with all the data was created and I saw it in the UI version. I tried to handle the case when user leaves the page – to save the data to notion anyway. There were some validation errors, but I fixed them. Then I got the error

   data: {
      object: 'error',
      status: 400,
      code: 'validation_error',
      message: 'Unsaved transactions: Unrecognized error.'
    }

I removed all the new code with git stash and returned to the previous working version. Rebuilded the project, started the server once again, and reloaded the page. But I still get the same error.