BizTalk 2020 - Failure to suspend messages on error - Office365 Outlook Email

I'm using Microsoft BizTalk Server 2020 with Office365 Outlook Email adapter in a Receive Port.

Adopting a custom pipeline (with custom component) receiving a mail, when a pipeline error occurs, the message doesn't suspend and I've these errors in the application event log:

(Names omitted)

If I put PassThru pipeline into Receive Location, obviously I don't have any issue: the mail is read correctly and sent to Message Box.

But, for the application I'm developing, I need to check the attachment name and suspend bad messages.

The Custom Component tries to receive attachment information, and if the attachment name doesn't respect some condition, I have to suspend the message.

Here the code:

public Microsoft.BizTalk.Message.Interop.IBaseMessage Execute(IPipelineContext pContext, Microsoft.BizTalk.Message.Interop.IBaseMessage pInMsg)
{
	if (pInMsg.BodyPart != null)
	{
		string emailAttachmentName = "NOT_FOUND";

		// Loop through the message parts (mail attachments)
		for (int i = 1; i < pInMsg.PartCount; i++)
		{
			// Save the name of the part/attachment into partName
			pInMsg.GetPartByIndex(i, out string partName);
			
			// Check if extension of attachment is .ang
			if (Path.GetExtension(partName).ToLower() == ".ang")
			{
				// Save the name to var and exit loop
				emailAttachmentName = partName;
				break;
			}
		}

		// If not found, suspend the message
		if (emailAttachmentName == "NOT_FOUND") throw new ApplicationException("ERROR.");

	}
	return pInMsg;
}

I have only these 3 logs, no message suspended in the Administration console and the only two ways to see if pipeline fails are:

1. checking physical mail folder to see if message has been read or not
2. checking event log

After a few minutes of having these errors, the receive port tried to read the mail one more time and once again I got the errors (and so on...).

I've also installed CU4.

Is there a way I can suspend the message in the Administration console?

The main problematic mistake is the second one:

I've tried to change adapter handler, restart instances, change mail address and folder, force routing message port errors, install CU4