sim not supported on an unlocked phone

Hi,

I recently unlocked my IPhone SE to use abroad. I bought it in the UK and the original carrier was Vodafone.

After it was unlocked I put a Lebara SIM in it and it worked fine. I tested it out in Southern Ireland with no issues.

I've just arrived in Hong Kong, where £5 of Lebara data lasts approx 30 seconds. I went to a local shop in Hong Kong and bought an airsim. When I put the airsim into the phone I get an "Activation Required. Dismiss." pop up and the first screen that comes up is "Update Completed. Your iPhone was updated successfully. There are just a few more steps to follow, and then you're finished!". I click CONTINUE and get "It may take a few minutes to activate your phone" followed by the "SIM Not Supported" screen.

The airsim started to work for a few seconds during one of the many "Try Again"s but I'm still having no luck.

I tried wiping the phone and rebooting it to no avail. The airsim has data on it so that's not the problem either.

Airsim is working for the people I'm travelling with so I;ve no idea what problem is!

Please help! I desperately need Google Maps to survive!