How do I send texts from Earthmate

The Mini 2 as you discovered does not work with Earthmate.  The Garmin Explore app is what you want to use.  As for why your Mini 2 could not acquire a location, I assume that your device had a clear view of the sky.  I have the Messenger app on my phone but I haven't used it, but I believe it is only about messages.  It will send messages over the cellular network when that is available, and over the Iridium network when out of cellphone coverage.

Both the M1 and M2 are notorious for slow acquisition or failure to acquire. 

I believe the M2 uses an EPO file to speed up a cold start. Sync with the explore app to get a current EPO. 

For both M1 and M2, you can also do a 20 minute “soak” with a clear sky view in order to download the current almanac from the GPS satellites. Power up, ask the unit to display your coordinates, set the unit down, step away and let it sit for 20 minutes.

Personally, I always check to be sure I HAVE a fix before I start moving. Every. Single. Time.

On the trail, the conventional wisdom is to carry the unit high on your shoulder - for example, on a pack strap. Never IN the pack. Never in jacket or pants pocket.

As said before, you have tried to use unfortunately the wrong app. Earthmate is not compatible with the mini 2 - I would use the Explore app, not the Messenger App (Messenger app is hijacking your phone number).  As twolpert mentioned, the mini 2 uses an EPO file for a quicker gps fix, which is downloaded while syncing your device with the Explore app. And important, as twolpert already has mentioned, the way you mount your mini 2. Good luck for the next trip

vanderloo said:

I should probably take some of the blame but I have to say I find it very frustrating that in order to use my device I need to download 5 or 6 apps and it's very confusing to me what does what. 

Nope, not some blame. This was 100% your own fault.

If you had taken a brief look at the Owner's Manual, you would have had instructions on set up and use.

https://support.garmin.com/en-US/?partNumber=010-02602-00&tab=topics

twolpert said:

Both the M1 and M2 are notorious for slow acquisition or failure to acquire. 

My experience on the inReach Mini 2 with GNSS enabled is that it does fast location acquisition, similar performance to the latest iPhone. Stop beating the jungle drum on this issue.

Depends on whether or not the EPO is up to date.

You have written that sentence many times, and it is false. Regardless of EPO. Those two devices
perform very differently on finding location. I have no complaints about the Mini 2’s
ability, stability, or speed on getting a GPS fix.

Nor have I read reports on this being a problem. If you still maintain that the M2 is notorious for slow acquisition or failure to acquire – please share details.

Time to acquire from a cold start is a matter of whether or not the device has an almanac for the current date/time/location. Without a current almanac, the unit degenerates to a full sky search to determine which satellites are in view. For GPS, there are two basic ways to get the almanac - an up to date EPO file or downloading it from the GPS constellation. The download is time-consuming (minimum of 12 or 13 minutes, usually more like 20) and works best (most quickly) when the unit is stationary. 

Once the initial almanac is on-board, it is automatically maintained while you use the unit.

Phones get the equivalent information using a technique called "assisted GPS" (when the phone has cellular connectivity). The required information is downloaded from the connected cell tower. 

I have no idea if multi-GNSS improves this. I am not familiar with the particulars of the "almanac" equivalent in other systems. However, the principle is the same. The unit needs to know which satellites are overhead.

My experience with the M2 is that is is slow to acquire from a cold start if the EPO is not up date (and the unit has not been used for some time, leading to an outdated onboard almanac). A warm start is an entirely different beast since the almanac is (by definition) up to date.

My main complaint about both the M1 and the M2 is (apparently) the GPS antenna design. You need a very clear sky view in order to use the unit at all. This manifests as poor initial acquisition time if you don't carry the unit carefully. For example, carrying the unit in your hand at your side leads to problems with acquisition. Anecdotally, I have seen that myself.