Medicare plan B payments are qualified as Self-employed medical insurance premiums and should be entered under Business instead of in the Social Security Benefits entry area. So go back and take it off your SSA-1099 entry.
You don't have to manually enter it or override anything. Just don't enter it from the SSA-1099 and enter it in the interview steps as regular ins under business.
Self Employed health Insurance does not go directly on Schedule C so it will not reduce your Net Profit or self employment tax.
If your health ins exceeds your net self-employment income it gets split. An amount equal to your net self-employment income goes on Form 1040 Schedule 1 line 17 (to 1040 line 10) and the remainder gets added in to medical expenses on Schedule A.
