Star Sizing and Grid Size Sharing in WPF
They don’t work together. Full stop. Thank you Microsoft. The only way around this is to manually bind your columns/rows of one grid to another instead of using star sizing. Thanks to this article we can use this:
<Grid.ColumnDefinitions>
<ColumnDefinition Width="{Binding ElementName=OtherGrid}, Path=ColumnDefinitions[0].Width}" />
</Grid.ColumnDefinitions>
