Garmin Connect - empty fields of profile, pulse zones and power zones

Looks like a networking problem, or being blocked by CloudFlare (kind of firewall service Garmin uses to protect their servers). I would test it with an alternative Internet connection.

Alternative Internet channel tried, all traffic is directed through VPN server (Netherlands), no change.
Setting the FTP in the app doesn't work either, it doesn't save, that's sad
Garmin Connect Web all work fine.

Igorinho said:

all traffic is directed through VPN server (Netherlands)

Perhaps there is a different problem, but CloudFlare often denies access from many VPNs, since they tend to be abused by hackers for hiding their location. I would try it with an alternative local Internet provider instead.

You could try reinstalling the app, although you told you get the same result on two phones, so it is not very likely to help. Installing an older version of the app from apkmirror.com would be worth of trying too. Otherwise, reach out to your local Support, and in the meantime change the parameters directly on your Edge.

I have been experiencing the same problem for a year now with EDGE 840.