Can I amend my tax return that I already amended again if I didn't do something right the first time?

I filed an amend on my return and uploaded my 1099R form but I think I checked a couple wrong boxes because the IRS states they were unable to process my amended return because they can't verify the income or withholding amount claimed which it shows it all on the 1099R form I uploaded and sent to them.

After you file

You can amend  as many time as you want, but it is best to wait until the current amend has been completed before sending another amend.

After you file

"Explanation : This is amendment No.2 based on previous amendment No.1 already filed.

The additional changes here are as follows. 

<supply details>"

 

That's how I do it.

@Angel_eyes_4eva