I have dealt with this problem before. Restart your phone, turn on roaming and set your preference to 4G/LTE as the 5G will not work everywhere especially outside metropolitans. Best of luck.
There is also another way if you are going on a trip that lasts longer than 15 day to the US. You can switch to a Canada/US account that is giving you freedom of calls/text and a lot of data (currently 50Gigs). If you travel often to US keep the plan...
