“Feedback Required” error
Best solution is to pause activity for a few days and use the official Instagram app. It’s recommended to do some actions (ex: change profile pic, update info, post, etc.) in the official app and/or official site these days. But this solution is not 100% efficient.
For new Instagram accounts, errors like this do occur if you have not verified your account, especially with a mobile number AND if you’ve not used the account on the official Instagram mobile app. In this case, we advise you to verify the account (preferably with a mobile number) and also perform tasks such as Follow, Like and comment on the official Instagram mobile app.
Also consider to start with the lowest speed to send bulk messages.