getUri() delivers always null on AuditAuthor and AuditResource

I am modifying my plugin regarding the Auditlog changes, since the recently used classes getting deprecated. So far nearly everything is working, but I still struggle with getUri(). This does always return null. So I never can link an affected object like a project or an author. But I can extract any other AuditAuthor method like .getId(), .getName() and so on. That does work well either for the author and for affected Objects (AuditResource). I added the most important part of my code below. May be someone has an idea what is wrong and can give me some hint?

PageRequest.Builder<AuditEntityCursor> auditEntityCursorPageRequestBuilder = new PageRequest.Builder<AuditEntityCursor>();
		
		auditEntityCursorPageRequestBuilder.offset(iOffset); /* similar to the value from legacy API example */
		auditEntityCursorPageRequestBuilder.limit(iLimit); /* number of results, up to PageRequest.Builder.MAX_PAGE_LIMIT */
		
		PageRequest<AuditEntityCursor> auditEntityCursorPageRequest = auditEntityCursorPageRequestBuilder.build();
		
		Page<AuditEntity, AuditEntityCursor> auditEntityCursorPage = null;
		Iterator			iterator = null;

		try{
			// Query
			auditEntityCursorPage = auditSearchService.findBy(auditQuery, auditEntityCursorPageRequest);
		}
		catch(Exception e){
			// show error message
			jsonAuditLogErr.add("auditEntityCursorPage Exception: " + e.toString());
		}
		
		try{
			// Get actual results from the response
			List<AuditEntity> listauditlogs = auditEntityCursorPage.getValues();
			
			iterator		= listauditlogs.iterator();
		}
		catch(Exception e){
			// show error message
			jsonAuditLogErr.add("AuditEntity Exception: " + e.toString());
		}
		
		if(iterator != null){
			while(iterator.hasNext()){
				// get general record data ////////////////////////////////////////////////////////////////////////////////////////////////////////////
				AuditEntity				auditlog		= (AuditEntity) iterator.next();
				
				JsonObjectBuilder	jsonAuditRec	= Json.createObjectBuilder();
				
				if(auditlog.getTimestamp() != null){
					//jsonAuditRec.add("timestamp", sdFormatter.format(Date.from(auditlog.getTimestamp())));
					jsonAuditRec.add("timestamp", Date.from(auditlog.getTimestamp()).toInstant().toString());
				}
				if(auditlog.getAuthor() != null){
					JsonObjectBuilder jsonAuthor = Json.createObjectBuilder();
					
					jsonAuthor.add("name", auditlog.getAuthor().getName());
					jsonAuthor.add("type", auditlog.getAuthor().getType());
					jsonAuthor.add("id", auditlog.getAuthor().getId());
					
					if(auditlog.getAuthor().getUri() != null){
						jsonAuthor.add("uri", auditlog.getAuthor().getUri());
					}
				}
...
				// ::.. affectedObjects ..::
				JsonArrayBuilder 	jsonAffObjs	= Json.createArrayBuilder();
				
				if(auditlog.getAffectedObjects() != null){
					List<AuditResource>	lAffObj		= auditlog.getAffectedObjects();
					
					for(AuditResource affObj : lAffObj){
						JsonObjectBuilder jsonAffObj = Json.createObjectBuilder();
						
						jsonAffObj.add("name", affObj.getName());
						jsonAffObj.add("type", affObj.getType());
						
						if(affObj.getId() != null){
							jsonAffObj.add("id", affObj.getId());
						}
						if(affObj.getUri() != null){
							jsonAffObj.add("uri", affObj.getUri());
						}
						
						jsonAffObjs.add(jsonAffObj);
					}
				}
...