Did your spouse owe money before they entered the tuition for the year? If they did, it’s possible that the tuition is being used to reduce the tax owing to nil, so there is nothing left to transfer.
If you are using TurboTax Live Assist & Review, and have more questions, you can talk to a tax expert: https://turbotax.community.intuit.ca/replies/3456106
He didn't owe any taxes before entering any tuition amounts. Once the tuition was entered, his refund was larger though. It was basically the same setup last year and I was able to transfer the tuition last year, but not this year.
If you are still unsure of what is going, you can contact the TurboTax Live Assist & Review folks as per the FAQ above and they can go over your return and see what is going on.
I am having the same issue and there doesn't seem to be an answer available anywhere.
Please contact our phone support team at 1-888-829-8608 as they will be better able to assist you.