I am working on this code to send an email with an .ics attachment, everything seems to be working ok, except the Description in the .ics attachment is not populating. Could anyone advise on why that might be? Thanks in advance for the help!

public class AttendeeConfirmationEmail{
    public static void sendEmail(List<Attendee__c> Attendees) {
        List<Attendee__c> attendeelist = [Select  ID, Training_Event__r.Start_Date_Time__c, Training_Event__r.End_Date_Time__c, Training_Event__r.Location__c, Contact__r.Email, Contact__r.FirstName, Contact__r.LastName, Training_Event__r.Name, Confirmation_email_sent__c, Training_Event__r.Webinar_Dial_in__c, Training_Event__r.Webinar_Access_Code__c, Training_Event__r.Webinar_Info__c
                                          From Attendee__c 
                                          Where Status__c = 'RSVP - Yes' AND Id in :Attendees];
        List<Attendee__c> attendeeupdate = New List<Attendee__c>();
        OrgWideEmailAddress[] owea = [select Id from OrgWideEmailAddress where Address = 'test@email.org'];
        List<Messaging.SingleEmailMessage> EmailList = New List<Messaging.SingleEmailMessage>();
        for(Attendee__c a : attendeelist){
            if(a.Confirmation_email_sent__c == False){
                DateTime startDate = a.Training_Event__r.Start_Date_Time__c;
                String formatted_startDate = startDate.format('yyyyMMdd\'T\'Hmm\'00\'');
                String formatted_startDateII = startDate.format('MMMM d,  yyyy \'at\' h:mma');
                DateTime endDate = a.Training_Event__r.End_Date_Time__c;
                String formatted_endDate = endDate.format('yyyyMMdd\'T\'Hmm\'00\'');
                String dialin = a.Training_Event__r.Webinar_Dial_in__c;
                String accesscode = a.Training_Event__r.Webinar_Access_Code__c;
                String location = a.Training_Event__r.Location__c; 
                String body = + 'Thank you for registering for '
                              + a.Training_Event__r.Name
                              + ' on '
                              + formatted_startDateII
                              + '. '
                              + 'The training will be held at ' 
                              + a.Training_Event__r.Location__c
                              + '. '
                              + 'To cancel and/or register for a different training session, please email test@email.org'
                              +(a.Training_Event__r.Webinar_Dial_in__c == Null ? '' : (' \r\n' + ' \r\n' + 'Conference Dial-in Number:' + ' ' + a.Training_Event__r.Webinar_Dial_in__c))
                              +(a.Training_Event__r.Webinar_Access_Code__c == Null ? '' : (' \r\n' + 'Participant Access Code:' + ' ' + a.Training_Event__r.Webinar_Access_Code__c))
                              + ' \r\n' + ' \r\n' 
                              + 'Best,' + ' \r\n'
                              + 'Training Team';
                String subject = a.Training_Event__r.Name + ' confirmation'; 
                String fromAddress = 'test@email.org'; 
                String displayName = a.Contact__r.FirstName + ' ' + a.Contact__r.LastName;
                String toAddress = a.Contact__r.Email;
                    if(toAddress != null){
                        String attachmentName = 'Meeting.ics';
                        Messaging.SingleEmailMessage msg = new Messaging.SingleEmailMessage();
                        msg.setOrgWideEmailAddressId(owea.get(0).Id);
                        msg.setToAddresses(new String[] {toAddress});
                        msg.setSubject(subject);
                        msg.setUseSignature(false);
                        msg.setPlainTextBody(body);
                
                        Messaging.EmailFileAttachment efa = new Messaging.EmailFileAttachment();
                        efa.setFileName(attachmentName );
                        Blob b = doIcsAttachment(formatted_startDate, formatted_endDate, location, body, subject, fromAddress, displayName, toAddress, dialin, accesscode);
                        efa.setBody(b);
                        msg.setFileAttachments(new Messaging.EmailFileAttachment[] {efa});
                        
                        a.Confirmation_email_sent__c = True;
                        attendeeupdate.add(a);
                        EmailList.add(msg);
                    }
            }
        }
        system.debug('Email list size: ' + EmailList.size());
        if(EmailList.size()>0){
            Messaging.SendEmailResult[] results = Messaging.sendEmail(EmailList);
        }  
        if(attendeeupdate.size()>0){
            update attendeeupdate;
        }
    }
        private static Blob doIcsAttachment(String formatted_startDate, String formatted_endDate, String location, String body, 
                                            String subject, String fromAddress, String displayName, String toAddress, String dialin, String accesscode) {
                    // Now Contruct the ICS file
                    String [] icsTemplate = new List<String> {'BEGIN:VCALENDAR',
                        'PRODID:-//Schedule a Meeting',
                        'VERSION:2.0',
                        'METHOD:REQUEST',
                        'BEGIN:VEVENT',
                        'DTSTART: ' + formatted_startDate,
                        'DTSTAMP: '+ String.valueof(DateTime.Now()),
                        'DTEND: ' + formatted_endDate,
                        'LOCATION: ' + location,
                        'UID: ' + String.valueOf(Crypto.getRandomLong()),
                        'DESCRIPTION: ' + dialin,
                        'X-ALT-DESC;FMTTYPE=text/html: ',
                        'SUMMARY: ' + subject,
                        'ORGANIZER:MAILTO: ' + fromAddress,
                        'ATTENDEE;CN="' + displayName + '";RSVP=TRUE:mailto: ' + toAddress,
                        'END:VEVENT',
                        'END:VCALENDAR'
                    };
            String attachment = String.join(icsTemplate, '\n');
            return Blob.valueof(attachment); 
        }
}