iMessage always as SMS from iPhone but not iPad
I am connected to WiFi and want to send an iMessage to my wife with my iPhone. The text is immediately displayed in green. When I take my iPad (only WiFi) and type the message it works fine as iMessage and arrives on my wife’s phone. All other contacts I have get my message always in blue.
I have tried switching off/on the phones, switching off/on iMessage on both our phones but that did not help. My wife is in the contacts, also as emergency, both email address and phone no. are correct.
What else should I try?
Thanks.
iPhone 12