I have isolated a reproducible animation issue involving SwiftUI List, system .swipeActions, variable row heights, and ProMotion. Environment: iPhone 17 Pro Max iOS 26.6 Xcode 26.5 Low Power Mode off “Limit Frame Rate” off iOS screen recording off When a List contains alternating single-line and two-line rows whose heights are determined naturally, slowly dragging a row left to reveal .swipeActions causes a visible pause. The row briefly stops following the finger, then jumps left. The trailing action buttons appear suddenly instead of being progressively revealed. Fast swipes are usually smooth. I created a minimal project with two modes: Variable: alternating single-line and two-line rows use their natural heights. Uniform: the same contents are constrained to a uniform height. Both modes use the same List, SF Symbol, tap gesture, and .swipeActions. The issue reproduces consistently in Variable mode, while Uniform mode remains smooth. A simplified version of the Row is: ForEach(0..<20, id: \.self) { index in HStack { Image(systemName: "folder") .frame(width: 28) VStack(alignment: .leading) { Text("Category \(index + 1)") if index.isMultiple(of: 2) { Text("Secondary information") .font(.caption) .foregroundStyle(.secondary) } } Spacer() } .swipeActions(edge: .trailing, allowsFullSwipe: false) { Button("Delete", systemImage: "trash") {} .tint(.red) Button("Hide", systemImage: "eye.slash") {} .tint(.orange) } } The unusual part is that the issue immediately disappears when any of the following is enabled: Low Power Mode Accessibility → Motion → Limit Frame Rate iOS screen recording It returns as soon as those conditions are disabled. I can also observe highly similar behavior in: Settings → General → iPhone Storage Rows with a “Last Used” subtitle appear taller than rows without it. Slowly swiping those rows can produce the same pause followed by the action UI suddenly appearing. The same frame-rate-related workarounds make that system list smooth as well. I have filed this through Feedback Assistant: FB24515209. Has anyone reproduced this on another ProMotion device, another iOS 26 version, or an iOS 27 beta? I am especially interested in whether there is a framework-supported workaround other than keeping all swipeable rows at a uniform height.