you can set /serveStaleOnError in dispatcher to serve stale content. https://helpx.adobe.com/experience-manager/kb/ServeStaleContentOnError.html 

Did you check your dispatcher configurations for headers?content-disposition settings. (inline / attachment etc)

you can raise a ticket in apple forums.Note that Big Sur breaks the previous behaviour of the JAVA_HOME environment variable to pick the Java version used to run the command-line tools. If this matters to you, consider filing an bug report. Or you can start install the Java new version

Select the user that will be responsible for this site.Many organizations find it useful to have a site/ product owner who works to ensure that the vision of the project is met by the individual teams during implementations (content creation, new features implementation)I don't see it (siteOwner) us...

declare LinkURL ValueMap variable @ValueMapValue(injectionStrategy = InjectionStrategy.OPTIONAL)private String linkURL;  ====The best practice is to declare interface and then implement:1) CustomTeaser Interface public interface CustomTeaser extends Teaser { default String getLinkURL() {      ///} }...

Is this project already deployed?Change the version and try to deploy

http://localhost:4502/libs/granite/security/content/v2/usereditor.html/home/users/system/QqFW4BXSK4uuRJzOXE8Z http://localhost:4502/libs/granite/security/content/v2/usereditor.html/home/users/system/W5o5TAoKqbqfdjC3fbpc check these async job servicesFor running Jobhttps://experienceleague.adobe.com/...

Can you give your source code and complete error log trace?

Two scenarios can apply1) In one of our use case, we implemented a workflow that will trigger when an asset is modified to Invalidate CDN cachepublic void execute(final WorkItem workItem, final WorkflowSession workflowSession, final MetaDataMap arg)throws WorkflowException {try {Asset asset = getAss...

If your second paragraph contains any List Items (1. xxx 2.ccc etc) , then this text will not come under Paragraphed and the Paragraph icon will disable,If your second copy is plain text, then it will treat as Paragraph.