I have the same issue

Found the solution....this is happening because you have not entered an RRSP contribution (possibly didn't check the rrsp contribution box in the profile section).

I am having the exact same issue - the amount from line 21 is not populating on line 24 - to reflect my HBP repayment entered accurately.  The proposed solution to check the RRSP box in profile was not the issue as it was already selected.

Please help.

Thanks

Did you also enter your RRSP contribution amount?

Yes I did, I found out the reason was due to the rrsp itself and how it was set up. I spoke with turbo tax rep and got it all cleared out. Thank you so much for the follow up. This is closed issue now.