Thank you - additional details and testing - I was able to duplicate on 3 clients:

Personal 1040 - MFJ and HOH.

Sch A input,  Scr25 60/100% Cash Contr line.  Total Sch A below standard deduction.

Sch K1 - Partnership - .

K1 Partnership, Line 13 - Code G Cash Contributions - any figure would override the Sch A amount, or other K1 Line 13 Code A input.  However, clients with multiple K1's the Code G would add up and transfer to 1040 Line 12B.

If I used K1 Line 13 code A instead, then all charity was being properly add to Sch A input  and reflected properly on 12B.

Strange stuff - just going to change K1 input code to A, or use the Screen 25 Charity Override.

Crazy stuff.