I am editing a SharePoint Online master page.
Commented out below mention, complete h1 section but still site title "Trial" is showing on the page.
<h1 id="pageTitle" class="ms-core-pageTitle">
<!--SPM:<SharePoint:AjaxDelta id="DeltaPlaceHolderPageTitleInTitleArea" runat="server">-->
<!--SPM:<asp:ContentPlaceHolder id="PlaceHolderPageTitleInTitleArea" runat="server">-->
<!--SPM:<SharePoint:SPTitleBreadcrumb
runat="server"
RenderCurrentNodeAsLink="true"
SiteMapProvider="SPContentMapProvider"
CentralAdminSiteMapProvider="SPXmlAdminContentMapProvider"
SkipLinkText="">-->
<!--PS: Start of READ-ONLY PREVIEW (do not modify)--><span id="ctl00_DeltaPlaceHolderPageTitleInTitleArea">Home</span><!--PE: End of READ-ONLY PREVIEW-->
<!--SPM:<PATHSEPARATORTEMPLATE>-->
<!--SPM:<SharePoint:ClusteredDirectionalSeparatorArrow runat="server"/>-->
<!--SPM:</PATHSEPARATORTEMPLATE>-->
<!--SPM:</SharePoint:SPTitleBreadcrumb>-->
<!--SPM:</asp:ContentPlaceHolder>-->
<!--SPM:</SharePoint:AjaxDelta>-->
<!--SPM:<SharePoint:AjaxDelta BlockElement="true" id="DeltaPlaceHolderPageDescription" CssClass="ms-displayInlineBlock ms-normalWrap" runat="server">-->
<a href="javascript:;" id="ms-pageDescriptionDiv" style="display:none" data-accessibility-nocheck="true">
<span id="ms-pageDescriptionImage">
</span>
</a>
<span class="ms-accessible" id="ms-pageDescription">
<!--SPM:<asp:ContentPlaceHolder id="PlaceHolderPageDescription" runat="server"/>-->
</span>
<!--SPM:<SharePoint:ScriptBlock runat="server">-->
<!--SPM:_spBodyOnLoadFunctionNames.push("setupPageDescriptionCallout");-->
<!--SPM:</SharePoint:ScriptBlock>-->
<!--SPM:</SharePoint:AjaxDelta>-->
<!--SPM:_spBodyOnLoadFunctionNames.push("setupPageDescriptionCallout");-->
and check if its working.