How to completely remove the horizontal “ghost lines” inside List with Section and custom rows?

I’m working on a screen that uses a single SwiftUI List composed of:

1. a top block (statistics, month picker, year selector, total, Entrata/Uscita picker).
2. a list of transactions grouped by day, each group inside its own Section.
3. each row is a fully custom card with rounded corners (RoundedCornerShape)

I’m correctly removing all separators using:

.listRowSeparator(.hidden)
.listSectionSeparator(.hidden)
.scrollContentBackground(.hidden)
.listStyle(.plain)

Each row is rendered like this:

TransazioneSwipeRowView(...)
.listRowInsets(EdgeInsets(top: 0, leading: 16, bottom: 0, trailing: 16))
.listRowBackground(Color.clear)

However, I still see thin horizontal lines appearing between:

• the search bar and the top block
• the top block and the start of the list
• between rows inside the grouped section
• sometimes at the bottom of a Section

These lines are NOT:

• Divider()
• system separators
• backgrounds
• row borders

They seem to be “ghost lines” automatically generated by SwiftUI’s List when multiple consecutive rows or sections are present.

Goals

I want to remove these horizontal “ghost lines” completely while keeping:

• native SwiftUI List
• native scroll behavior
• swipe-to-delete support
• grouping by Section
• custom card-like rows with rounded corners

What I already tried

• .plain, .grouped, .insetGrouped list styles
• .listRowSeparator(.hidden) and .listSectionSeparator(.hidden)
• .scrollContentBackground(.hidden)
• clearing all list and row backgrounds
• adjusting/removing all padding and insets
• Spacer(minLength: 0) tests
• rebuilding the layout using ScrollView + LazyVStack (this works perfectly — no lines — but loses native swipe-to-delete)

There are no Divider() calls, and no background colors that could generate borders. The lines seem to be drawn by SwiftUI internally.

Question

Is this a built-in behavior of SwiftUI’s List in .plain style when using multiple custom rows? Or is there an officially supported way to eliminate these lines entirely?

More specifically, is there a recommended combination of modifiers to achieve:

• a List with grouped Sections
• fully custom rows with rounded corners
• no horizontal separators at all, even in the empty gaps between sections?

Any guidance, documented workarounds, WWDC references, or official recommendations would be greatly appreciated.