Won't connect in Denmark

- Member Since: Jul 7, 2017
I've had an LG Aristo for about a month traveling around in the US with no problems.
Upon arriving in Copenhagen, Denmark it simply refuses to connect to either of the networks it detects;
Telia-Telenor DK or TDC. All international roaming options are on and the two website profile roaming restrictions are in the OFF positions.
Tech support says TDC should be the correct network but every attempt at registering on either or in auto returns, "Unable to connect to the network at this time. Please try again later."
If I go to Settings/Networks/Call/More/Call barring, it returns "Call settings error. Network or SIM card error"
If I go to Settings/Networks/Call/More/Additional settings, it twirls for a minute and returns, "Network or UIM card error"
If I go to Settings/Networks/more/Mobile networks, 'Mobile Data' and 'Data roaming' are both ON, Network mode is set to GSM/WCDMA/LTE auto
If I go to Settings/Networks/Mobile networks/Network operators, it is set to 'Select automatically', although I have tried both of the detected operators
individually without success.
If I got to Settings/networks/Mobile networks/Access Point names, the "T-Mobile LTE' option will not stay checked.
VoLTE is on.
WiFi Calling is on - Cellular preferred
It makes no difference if WiFi is on or off.
In the upper left of the home screen is says 'T-Mobile' indicating it at least recognizes the proper network.
Anybody got a clue as to why this is happening? If the SIM card was bad it wouldn't have worked in the US, right?