I am working on 2019 tax returns for two children that have investment income and must file forms 8615.  Their parents have zero taxable income.  When I check the box on Screen 43 to elect to calculate the tax using parent's tax rate and then use the family link feature, Lacerte computes the children's tax using trust tax rates.  When I go back to Screen 43, the box to elect to calculate the tax using parent's tax rate is unchecked.  Is there a problem with the software or am I missing something?