Please tell us some basic information before asking for help:
Model Name:Zenfone 9
Rooted or not:not
Frequency of Occurrence: Every time
APP Name & APP Version (If your issue relates to the app):
In addition to information above, please also provide as much details as you can, e.g., using scenario, what troubleshooting you've already done, screenshot, etc.
I'm in Australia, 2nd SIM card is a Chinese Unicom 4G card. After power on, the roaming card will be on line for a few minutes and then will come in a "No Service" status. Switching to airplane mode and back will repeat this sequence.
Switching the slot won't solve the problem.
The roaming card works fine on other phones, including dual SIM phones.