Reminders in Agenda - potential issue?

What I did: I have notes created in agenda that are linked to dated calendar items. Example. Event on 10/30 at 3 pm
In that note I also created 2 reminders:
On 10/26 confirm event details for the 10/30 event (so the reminder is set for Oct. 26 and the subject says "confirm event details for 10/30 event) - I use the date as there are several events for this venue.
On 10/26 confirm event details for 10/30 event with volunteers (again, reminder set for 10/26 and subject has 10/30 date so I can quickly see which event I’m getting a reminder for).

What happened: The reminders seem to be syncing ok with Apple reminders. However, the icon in agenda is sometimes showing the reminder with an X through the clock icon, which to me means there is an issue. But what the issue is, I’m not sure. I tried changing the format of the date in the subject from 10/26 to Oct 26. Same thing. Usually the first reminder is good. It’s the second or third one in the note that shows the X. I can’t tell any difference in the reminders that look good and those that have the X. Right now they’re syncing but I’m worried that those with the X may at some point stop syncing with reminders.

I’m entering these via my Mac Book Pro on Agenda Version 11.0.1 (150). The reminders and notes are syncing on my iPhone 11 Pro Max (in Agenda on iPhone the same reminders are Xed out)

One thing I noticed (so far) is if I go into my phone and click the reminder and just hit save, the reminder does seem to stay as a clock icon/green in both my phone and Agenda on my Mac but frankly that’s tedious to go in and “update” everything I entered on my Mac.

The grey X means that Agenda can’t find the note anymore in the Reminders app or database. This can happen if for example not all reminders are synced to your phone (sometimes it’s set to only sync the current two weeks of reminders for example, so reminders too far in the future aren’t yet synced to the phone). Unfortunately Apple’s reminders implementation isn’t the most easy to deal with, we’ll try to see if we can reproduce the issue and see if it can be made more reliable.

Thanks for the reply. One of the reminders is set for Oct. 8, so well within the 2 weeks.

Ok what MAY be happening is I forgot my Apple Reminders forwards to the Due app. So maybe once Due pulls them from Reminders it is triggering the X in agenda. The reminders created in Agenda ARE in Due so I guess syncing is still working, it’s just making Agenda not know what to do with it.

Ah, that could indeed be the case if Due edits/saves the reminder, thanks for the follow up, we’ll keep that in mind.