See if these help:

https://proconnect.intuit.com/support/en-us/help-article/multi-state-taxes/entering-multi-state-amou...

https://proconnect.intuit.com/support/en-us/help-article/form-1040/allocate-amounts-multi-state-indi...

And this part: "The Percentage of Source Income field is not available for income such as Interest, Dividends, Pensions, Gambling winnings, or other Miscellaneous income. It is also not available for adjustments to income or deductions. Those must still be allocated to each state using the Allocate Multi-State Amounts option (+ sign)."