nested block diagram's dynamic width not worked as expected

[Sean10]

When i use the block diagram, it's normal. But if i add a block which wrapped j and k, It would leave a space after it, it cannot use up of the rest space.

Before adding block which wrapped j and k

block-beta
  columns 3
  a:3
  block:group1:2
    columns 2
    h i 
      j k
  end
  g
  block:group2:3
    %% columns auto (default)
    columns 5
    l m n o p q r
  end

After adding block which wrapped j and k, which is not worked as expected

block-beta
  columns 3
  a:3
  block:group1:2
    columns 2
    h i 
    block:group3:2
      columns 2
      j k
    end
  end
  g
  block:group2:3
    %% columns auto (default)
    columns 5
    l m n o p q r
  end

expected result

Originally posted by @Sean10 in #5467