@tobias_funke
FWIW not sure that’s a miscalculation:
As of 2022 (new instructions for Form 8960) you must include Schedule C income/loss on Line 4a, and then
enter the “non-passive” portion of that on Line 4b. Line 4c is equal to (4a - 4b).
So assuming your Schedule C loss was “non-passive” (i.e. a business in which you actively participated) the total on Line 4c should be $0
(-$1,000) - (-$1,000) = $0.
