为宏生成的PPT幻灯片添加音效导致动画随机异常变更

我正在制作一款游戏配套的演示文稿，用于展示玩家需达成的阶段（游戏本身无关）。每张幻灯片包含一个环形计时器（空心圆环），会在CycleTime时长内完成扫动，同时展示对应阶段的图片。由于存在诸多细节差异（如计时参数），幻灯片通过VBA宏自动生成。

未添加音效时，宏运行完全正常；但只要为任意动画效果添加音效，整个动画序列就会出现严重异常：

• 原本设置为**“与上一动画同时”的触发方式被自动改为“上一动画之后”**
• 动画时长被错误修改
• 淡入淡出效果丢失

我尝试过调整效果属性的赋值顺序、添加虚拟形状并为其绑定音效，均无法解决问题。

以下简化代码可复现该问题：同一子过程会在桌面生成两个单幻灯片演示文稿，二者本应仅音效存在差异，但实际动画表现完全不同。

Const CycleTime = 10
' CycleTime = 环形计时器扫动完成的总秒数；
' 第一个形状在前半段周期显示，随后淡出并被第二个形状替换。
Dim fn$
Public Sub MakeTestPresentations()
    fn$ = CreateObject("WScript.Shell").SpecialFolders("Desktop") & "Test@" & Format(Now(), "hhmmss")
    Call MakeASlide(UsingSound:=False)
    Call MakeASlide(UsingSound:=True)
Exit Sub
End Sub
Sub MakeASlide(ByVal UsingSound As Boolean)
Dim sldThis As Slide, swp As Shape, shp1 As Shape, shp2 As Shape
'   创建新的空白演示文稿
    Set pptSource = Presentations.Add
'   添加空白幻灯片
    Set sldThis = pptSource.Slides.Add(Index:=1, Layout:=ppLayoutBlank)
'   添加环形计时器形状，设置为CycleTime秒内完成扫动
    Set swp = sldThis.Shapes.AddShape(msoShapeDonut, 525, 83, 369, 369)
    swp.Fill.ForeColor.RGB = RGB(0, 0, 128)
    sldThis.TimeLine.MainSequence.AddEffect(Shape:=swp, effectId:=msoAnimEffectWheel, Trigger:=msoAnimTriggerWithPrevious).Timing.Duration = CycleTime
'   添加第一个形状：前半段周期显示，带淡入淡出效果
    Set shp1 = sldThis.Shapes.AddShape(msoShapeCloud, 83, 83, 369, 369)
    shp1.Fill.ForeColor.RGB = RGB(0, 255, 0)
    With sldThis.TimeLine.MainSequence.AddEffect(Shape:=shp1, effectId:=msoAnimEffectFade, Trigger:=msoAnimTriggerWithPrevious)
        .Timing.TriggerDelayTime = 0
        .Timing.Duration = CycleTime / 2
        If UsingSound Then .EffectInformation.SoundEffect.Name = "Laser"
    End With
    With sldThis.TimeLine.MainSequence.AddEffect(Shape:=shp1, effectId:=msoAnimEffectFade, Trigger:=msoAnimTriggerWithPrevious)
        .Timing.TriggerDelayTime = CycleTime / 2
        .Exit = True
    End With
'   添加第二个形状：后半段周期显示，带淡入淡出效果
    Set shp2 = sldThis.Shapes.AddShape(msoShape16pointStar, 83, 83, 369, 369)
    shp2.Fill.ForeColor.RGB = RGB(255, 0, 0)
    With sldThis.TimeLine.MainSequence.AddEffect(Shape:=shp2, effectId:=msoAnimEffectFade, Trigger:=msoAnimTriggerWithPrevious)
        .Timing.TriggerDelayTime = CycleTime / 2
        .Timing.Duration = CycleTime / 2
        If UsingSound Then .EffectInformation.SoundEffect.Name = "Drum Roll"
    End With
    With sldThis.TimeLine.MainSequence.AddEffect(Shape:=shp2, effectId:=msoAnimEffectFade, Trigger:=msoAnimTriggerWithPrevious)
        .Timing.TriggerDelayTime = CycleTime
        .Exit = True
    End With
'   保存演示文稿
    pptSource.SaveCopyAs fn$ & IIf(UsingSound, " (带音效)", " (无音效)"), ppSaveAsDefault
    pptSource.Close
Exit Sub
End Sub

内容的提问来源于stack exchange，提问作者Laminator