hook_block_type_form_alter don't return #validate and #submit for layout builder blocks

Problem/Motivation

If I use hook_block_type_form_alter() to alter a layout builder block it don't return #validate or #submit in $form variable. However for a normal block(created using block layout) it does return all the form values including #validate and #submit. So I am not able to add a custom validation or submit function to layout builder block forms. And even if I try to add $form['#validate] [] = 'validateMyBlock'; it's not working.