添加SupportsPinning后Outlook插件任务窗格仍无法固定求助

我按照官方文档指引，在manifest.xml中添加了<SupportsPinning>true</SupportsPinning>配置，但任务窗格仍无法固定。以下是我的manifest.xml内容：

<?xml version="1.0" encoding="UTF-8" standalone="yes"?><OfficeApp xmlns="http://schemas.microsoft.com/office/appforoffice/1.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:bt="http://schemas.microsoft.com/office/officeappbasictypes/1.0" xmlns:mailappor="http://schemas.microsoft.com/office/mailappversionoverrides/1.0" xsi:type="MailApp">  <Id>e08add90-caa6-4352-9749-c3612d8b2350</Id>  <Version>1.0.0.0</Version>  <ProviderName>My Taskpane App</ProviderName>  <DefaultLocale>en-US</DefaultLocale>  <DisplayName DefaultValue="My Taskpane App"/>  <Description DefaultValue="AI-Powered Email Workflows for Logistics, powered by My Taskpane App."/>  <IconUrl DefaultValue="https://localhost:3000/assets/icon-64.png"/>  <HighResolutionIconUrl DefaultValue="https://localhost:3000/assets/icon-128.png"/>  <SupportUrl DefaultValue="https://www.contoso.com"/>  <AppDomains>    <AppDomain>https://www.contoso.com</AppDomain>  </AppDomains>  <Hosts>    <Host Name="Mailbox"/>  </Hosts>  <Requirements>    <Sets>      <Set Name="Mailbox" MinVersion="1.1"/>    </Sets>  </Requirements>  <FormSettings>    <Form xsi:type="ItemRead">      <DesktopSettings>        <SourceLocation DefaultValue="https://localhost:3000/taskpane.html"/>        <RequestedHeight>250</RequestedHeight>      </DesktopSettings>    </Form>  </FormSettings>  <Permissions>ReadWriteItem</Permissions>  <Rule xsi:type="RuleCollection" Mode="Or">    <Rule xsi:type="ItemIs" ItemType="Message" FormType="Read"/>  </Rule>  <VersionOverrides xmlns="http://schemas.microsoft.com/office/mailappversionoverrides" xsi:type="VersionOverridesV1_0">    <Hosts>      <Host xsi:type="MailHost"/>    </Hosts>    <VersionOverrides xmlns="http://schemas.microsoft.com/office/mailappversionoverrides/1.1" xsi:type="VersionOverridesV1_1">      <Requirements>        <bt:Sets DefaultMinVersion="1.5">          <bt:Set Name="Mailbox"/>        </bt:Sets>      </Requirements>      <Hosts>        <Host xsi:type="MailHost">          <DesktopFormFactor>            <FunctionFile resid="Commands.Url" />            <ExtensionPoint xsi:type="MessageReadCommandSurface">              <OfficeTab id="TabDefault">                <Group id="DefaultGroup">                  <Label resid="GroupLabel" />                  <Control xsi:type="Button" id="taskPaneButton">                    <Label resid="TaskpaneButton.Label" />                    <Supertip>                      <Title resid="TaskpaneButton.OpenLabel" />                      <Description resid="TaskpaneButton.Tooltip" />                    </Supertip>                    <Icon>                      <bt:Image size="16" resid="Icon.16x16" />                      <bt:Image size="32" resid="Icon.32x32" />                      <bt:Image size="80" resid="Icon.80x80" />                    </Icon>                    <Action xsi:type="ShowTaskpane">                      <SourceLocation resid="Taskpane.Url" />                      <SupportsPinning>true</SupportsPinning>                    </Action>                  </Control>                </Group>              </OfficeTab>            </ExtensionPoint>          </DesktopFormFactor>        </Host>      </Hosts>      <Resources>        <bt:Images>          <bt:Image id="Icon.16x16" DefaultValue="https://localhost:3000/assets/icon-16.png"/>          <bt:Image id="Icon.32x32" DefaultValue="https://localhost:3000/assets/icon-32.png"/>          <bt:Image id="Icon.80x80" DefaultValue="https://localhost:3000/assets/icon-80.png"/>        </bt:Images>        <bt:Urls>          <bt:Url id="Commands.Url" DefaultValue="https://localhost:3000/commands.html"/>          <bt:Url id="Taskpane.Url" DefaultValue="https://localhost:3000/taskpane.html"/>        </bt:Urls>        <bt:ShortStrings>          <bt:String id="GroupLabel" DefaultValue="My Taskpane App Add-in"/>          <bt:String id="TaskpaneButton.Label" DefaultValue="Show Taskpane"/>          <bt:String id="TaskpaneButton.OpenLabel" DefaultValue="Open My Taskpane App" />        </bt:ShortStrings>        <bt:LongStrings>          <bt:String id="TaskpaneButton.Tooltip" DefaultValue="Open My Taskpane App" />        </bt:LongStrings>      </Resources>    </VersionOverrides>  </VersionOverrides></OfficeApp>

我已在Windows版Outlook桌面端和Outlook网页端进行了测试。

内容的提问来源于stack exchange，提问作者Nerdragen