on 25-01-2021 13:58
on 25-01-2021 14:02
Shortcode will only work in UK.
Are you in UK or abroad?
If in UK, have you topped up your sim to activate it Guide How to Top Up (PAYG)
Also check your message settings as you may have barred shortcodes and premium rate services from sending.
on 27-01-2021 22:28
on 27-01-2021 22:36
on 27-01-2021 22:36
You won't be able to port your number whilst in Poland, but your O2 sim should work there to call the UK and local calls.
Try manually searching for a different network to see if you get any reception.