Sonys Press conference from MWC took place end of February
If you missed it you can watch it here.
Please join the discussion here and share your thoughts on what was anounced here.
MWC 2019 discussion.
Based on the troubleshooting that you have already done on your own, it does sound like this is related to the hardware in the device, however just to make sure, take a look at the link below and make sure that the SIM card is inserted correctly, both in the SIM card tray and that the tray is inserted correctly in the device.
You can also contact your Local support team and see if they can arrange a new SIM card tray for you, just to make sure that we cover all the bases, so the device is not sent in when it doesn't need to be. However, should the device still not recognize the SIM card, it will need to be examined by a trained technician and the Local support team will arrange a repair for you.