I spent a lot of time troubleshooting and was about to pull the trigger on just mailing the tax return since I thought it was an error on Turbotax's part.
BUT, I ended up looking up the instructions for Form 8829 from the IRS website, which led me to the Line 11 Worksheet. After going through it, I realized that for 2025, its instructions are different from before, not in an intuitive way either.
After going through the Worksheet, I ended up omitting placing anything in column (b) Lines 11 and 17 on For 8829. Rather, I made a single entry in column (a) for Line 17. It's not as advantageous as using the same method as prior years (placing total property taxes paid split between Lines 11 and 17 column [b] and essentially multiplying them by the business percentage) as far as tax reduction, but at least I followed IRS's next instructions, which were adjusted to accommodate the increased SALT cap.
This ultimately cleared up all the errors on Form 8829 I was receiving.
Hope this helps
