Earthmate Messages only received from ''Unknown''

Am unclear on the situation. The tablet running the Earthmate app is paired with an inReach device? All messages in question are inReach to inReach? Or do I misunderstand the situation?

Absolutely correct. Cedar CT7 tablet has Earthmate app, which is paired with an Inreach device. All messages are inReach to inReach.

I don't have an active Explorer+ to test this with. 

If you log into the receiving account at the explore.garmin.com web site, how do the messages appear on the inBox tab? Knowing this might help narrow down the cause of the issue. In addition, if they are correct on the web site (and if you have Internet connectivity at the tablet location), this might provide a workaround.

On the garmin website I get the messages with their correct username's, no problem there. 

Would guess that the problem is unlikely to be firmware if that's the case. Although I suppose it could be a f/w update that's incompatible with the current Earthmate app. Do you have the latest Android version of the app? I know there was a release in the past few days, but I don't know the revision history.

Tablet has internet connection as well by the way.

Just looked at SE+/Explorer+ f/w release notes. There hasn't been a f/w release since 4.1 in September 2018. Although you might have installed it recently, the fact that this is over a year old argues against incompatibility between that f/w and the current release of the Earthmate app...

One other thing occurs to me. Are the addresses of the other iR devices in the contact lists on the various devices? That is, do you choose a recipient from contacts when you send or do you type the entire iR address manually? If these are contacts, everybody involved in the conversation has to have sync-d with the web site since the last change to the contact list. If all parties to the conversation do not have exactly the same contact lists, all kinds of weird things can happen.

This is because contact addresses are actually sent as very short "code numbers", not as the text of the contact address. The sending device looks the contact up in its address book. It sends the code number to the server. The server translates it into a real address and sends the message on. I would not be surprised if the Earthmate app does not do the same thing to display the sender address. So if the receiving iR device has a non-matching contact list, you might see incorrect or unknown senders. 

Is the sender also incorrect when you view the message on the iR device paired with the tablet? If so, that would be a tip-off that the paired device might have an incorrect contact list.

I think that might be the problem then in this case. Sender on Inreach device is also ''unknown''. But this would then mean to re-establish the contacts with their respective devices? 

Yes. For devices paired with mobile devices and the Earthmate app, I believe that an OTA sync via Earthmate would be sufficient. Otherwise, you're stuck with a wired sync directly with the web site. Depending on just who has old data, it might be sufficient just to sync your central device (the one paired with the tablet). But to be safe, you should do them all.

Is this an enterprise account with all devices on one account, or a bunch of individual accounts? Easier to handle if it's an enterprise account, but the principle is the same in all cases.