Check if your eSIM profile is activated on your iPhone.
Go to: settings > mobile data > under data plans, select the installed eSIM profile (or “secondary” or the name you renamed it)
Activate the profile by pressing the button Turn On This Line on the right.
As soon as your profile is activated, a double network signal will appear at the top of your screen.
NB: the double network only appears if you have also a physical SIM card/eSIM profile for voice & SMS installed on your device. If there is no physical SIM card installed, only the stepped bars network will be displayed.