One should NEVER amend a return until the original return has finished processing in full. Then you can amend the return but you CANNOT amend a second time until the first amendment has been fully processed. Filing any corrected return before the prior return has fully processed is a disaster waiting to happen.
Amended returns in a normal tax year take 4 to 6 months to process so don't be in a hurry to file another as we are not in a normal tax year.