Poll enrich with mail component will lose attachments

[Mi Jane 米静]

Dear community,

When I used Camel 3.11, poll enrich with mail component worked well and I could 
get the mail attachments.
When I changed to Camel 3.16 for other reasons, I could get the mail but I 
couldn’t get the attachments.

Here is an example:

……
.pollEnrich("imaps://{{mail.server}}?session=#oAuthSession&closeFolder=false&unseen=true&peek=true&folderName={{mail.sub.folder}}")
.process(new Processor() {
                @Override
                public void process(Exchange exchange) throws Exception {
                                AttachmentMessage attachmentMessage = 
exchange.getMessage(AttachmentMessage.class);
                                Map<String, DataHandler> attachments = 
attachmentMessage.getAttachments();
                                if (attachments != null) {
                                                LOGGER.info("attachments: {}", 
attachments.size());
                                } else {
                                                LOGGER.info("no attachment");
                                }
                }
})
……

With Camel 3.11 I got log “attachments: 1”, while with Camel 3.16 I got log “no 
attachment”.
Is it a known issue for Camel 3.16, or is there any extra parameter I missed? 
Thanks in advance!

Regards,
Jane