Before starting sprint we gave estimations, while discuss with my team, my project manager also part of the meeting. After three weeks my project manager start give list of tasks like this is API and this is front end and also estimations based on our previous sprint plan.

We pissed off. After that we never include our manager in technical meeting.

FYI - If you're using Google sheets for ball park estimations never give permission to your project manager to edit sheet.