UPDATE:
Per conversation with the WI DOR (2/25/2025), it IS correct that someone with over $10,000 (1 child) or $20,000 (2 or more) in dependent care expenses can benefit from the tax-free FSA Dependent Care Benefit (DCB) amount of up to $5,000 AND the WI credits calculated on up to $10,000 or $20,000.

RE: ProSeries' and TurboTax' handling of the error their software is generating when there is one child and a DCB amount equal to or greater than $3,000... I may have more to say on this after further conversations with them. In the meantime, until they fix this, the workaround (at least on PS) is as follows:

Override the federal 2441, lines 4 & 5 with the figures on lines 18 & 19 respectively. This should cause the earned income to flow to WI-2441 lines 7 & 8 and will then properly calculate any additional credit the taxpayer is entitled to. You'll likely have to turn off "error-checking" in order to e-file the return. I haven't gotten that far yet. Planning to error-check it for everything else though, before disabling error-checking to e-file a return.