Retirement tax questions

Not a 'Backdoor Roth'

 

When I enter $8000 into the IRA contribution data window it reduces the tax obligation by an expected sum, however, when the $8000 is entered into the data field for 1/1 to 4/15 the system states that "not eligible."

 

Perhaps it needs to be entered in both places?  Perhaps it's a technical error?  If I had an emoji to use, I would use a shrugging yellow character wearing a blue sweater....