solo Roth contribution entered Part 1 on line 7a and 7c - 19,500 and 6,500

Part III line 9 and line 17 indicates max contribution for each is 19,500 and 6,500

line 20 is calculated to be 25,000 (not 26,000)

Instructions for line 9 and 17 indicate max contribution is 19,500 and 6,000 (not 6,500)

Why discrepancy on worksheet and instructions?

The max contribution is 26,000 if over 50 - yes?