SwiftUI ScrollView scrolls when items added - swiftui

Question

In several places in my app, I implement a paged loading scheme using a ScrollView and a LazyVStack, with an ProgressView after the loaded items. The ProgressView is only shown if the model has more items to load, and on appear of the ProgressView, loading of the next page is triggered.
The new items get appended to the list in the model, and they get rendered, pushing the ProgressView off the bottom of the screen. When the user scrolls up, the ProgressView reappears, and triggers loading of the next page.
For some reason, in one list where I’m using a LazyVGrid inside a LazyVStack, when the next page loads, the entire view scrolls such that the bottom of the stack is still displayed, causing the ProgressView to sit there spinning. It’s as if the ScrollView is pinning the scroll to the bottom of its content, and I can’t figure out why.
The view looks like this:
ScrollView
{
LazyVStack
{
LazyVGrid(columns: self.columns, spacing: 20.0)
{
if let products = self.collection.products,
products.count > 0
{
ForEach(products)
{ inProduct in
NavigationLink(destination: ProductDetailsContainerView(searchResult: WNProductSearchResult(product: inProduct)))
{
ProductListingCell(imageURL: inProduct.imageURL,
title: inProduct.name,
listingCount: inProduct.availableCount,
price: inProduct.marketPrice)
}
}
}
}
if let products = self.collection.products,
products.count == 0
{
self.emptyDisplay
}
// Progress loader triggers loading…
if self.collection.hasMore
{
HStack
{
Spacer()
ProgressView()
Spacer()
}
.padding(.top, 40)
.onAppear { self.collection.load(next: 20) }
}
}
.padding(20)
}
Even more bafflingly, this only occurs after the second page loads. The first page loads as expected; then you scroll to the bottom, the ProgressView is revealed, the second page loads, and the items fill in without moving the scroll position. If you then scroll up again, the ProgressView is revealed, the third page loads, and the items fill in, but the scroll view is repositioned such that you’re looking at the new bottom of the list.
Hopefully you can see the behavior: