On my IRA worksheet, the box isn't checked that that says I converted the entire amount of the withdrawal and I did. Why?

Did you also put back and convert any withholding taken out?

No.

Well if they took out tax withholding and you didn't replace it when you converted then you did not convert the full amount.

I  didn't have taxes taken out. Converted amount to a Roth.

On a joint tax return, do they consider other 1099-R income when filling out this worksheet?

I'll page @dmertz 

All I can say is that when entering the Form 1099-R into TurboTax you must indicate the amount that you converted to Roth.

You might try deleting and reentering the 2020 Form 1099-R.  If TurboTax asks how much of the distribution was RMD, you must say that none of it was RMD.  Then indicate that you moved the money to another retirement account and either mark the box to indicate that you converted it to Roth or, if TurboTax does not present that option, indicate that you did a combination of rolling over, converting or cashing out, and enter the amount converted.