I was covered for 8 months in 2024 under a High deductable medical plan. TT calculates a max contrib of $6200. Why isn't this $6667 since I am over 60?

$6,200 is the correct amount:  $9,300 * 8 / 12 = $6,200.

(The full annual limit for family coverage of $8,300 plus the $1,000 catch-up is $9,300, not $10,000).