DEM it is unavailable?

EPO download by wifi and BT with mobile and GC.

This is from the Garmin Support section. 

"The file containing EPO information for your watch is usually updated when you sync the watch with Garmin Express or the Garmin Connect App. However, if the EPO file expires, your watch may take much longer to acquire a satellite connection." 

"Troubleshooting an Expired EPO

If your watch's EPO is expired, try the troubleshooting steps found below.

Sync the Watch

Syncing your watch with Garmin Express will usually update EPO. If you have an expired EPO on your watch, syncing with Garmin Express should be your first step to updating your EPO data. "

support.garmin.com/.../

My EPO data had expired and synching with Garmin Connect app wasn't working, so it then suggests the next step is to use a computer and sync using Garmin Express.

Just did this, and now the EPO is 'current'. 

BUS_TER said:

I can confirm DEM works correctly with the latest firmware (6.60).

Yes, you repeat what was told in the thread, except of the following

BUS_TER said:

You live in a region where Garmin does not have maps with altitude information available.

Which is highly unlikely, since practically all DEM sources have the whole globe coverage pretty complete. Garmin certainly does not mainatin any own DEM database, but is using one of the public data sources. So you would have to be in some military restricted secret zone, not to have DEM data available for the region.

For the moment, all those who complained about the DEM not being available for their region, and reported it on the beta firmware thread, eventually resolved the issue by resetting the watch. Data or connection outage may often play role in such issues. Missing data for a whole region yet to be proven.

I also have the issue when I test the new DEM altimeter calibration on my Instinct watches. (I have a Tundra and Lakeside Blue, since the Lakeside Blue came out later, and the issue is consistent for me across both of them on software version 6.60.)

It is great news to hear performing a soft reset on some customer's Instinct watch has resolved the issue. I was not able to confirm with my Instincts that the step resolved the issue. Our engineers continue to look into it. It should be solid and consistent for everyone when using the DEM option.

Garmin - Chris said:

I also have the issue when I test the new DEM altimeter calibration on my Instinct watches.

It is a pity you do not participate in the beta program for Instinct frmware It looks like the final version was prematurely released just because none of the beta testers reported any problems (apart from those resolved with the soft reset). 

Spit balling here but if a soft reset doesn’t solve the problem, maybe closing out GCM and restarting it may help, if getting DEM information is based on GCM?

I try it, BT, mobile data and Garmin Conect and DEM is working!

I have elevation automatic ON during activity by DEM...

Just one data point: For me DEM did not work until I removed the Instict watch from Garmin Connect and paired it again.