If I change TableView Style just to hide header / footer then there are thick black lines between items instead of light gray lines - same happens when hiding header / footer by code.
Was unable to find a setting in the style to change / reset.
When setting AdaptToStyle, the default style is applied. We will investigate here what exaclty is going wrong when updating the style when a custom style is applied, but as a temporary workaround you could hide the Header and Footer in code in the OnApplyStyleLookup event, without assigning a style to the TTMSFMXTableView: