Mistakes always cost money in terms of engineering hours spent fixing those mistakes. The feedback was poor and unacceptable from an engineering manager if the concerns are not backed by factual information and critical feedback to help steer you in the right direction you will not be able to grow.
In terms of your own self-improvement improve your internal processes for learning the code, and testing it before sending it off for a CR. Adding test cases for the work you do will help improve the quality of your work and enable it to be integrated easier into the overall codebase. If you need help or find issues with the code try to get clarification after spending time deep diving and learning and being curious (e.g., exhausted all other options).
Also note you can probably create your own dev pipeline so you can push to your hearts content and not break things, then only when things are working as expected submit a CR for others to review.
In terms of your own self-improvement improve your internal processes for learning the code, and testing it before sending it off for a CR. Adding test cases for the work you do will help improve the quality of your work and enable it to be integrated easier into the overall codebase. If you need help or find issues with the code try to get clarification after spending time deep diving and learning and being curious (e.g., exhausted all other options).
Also note you can probably create your own dev pipeline so you can push to your hearts content and not break things, then only when things are working as expected submit a CR for others to review.