iMessage: cannot use phonenumber, it's grey in settings (with a checkmark)

In this weekend I've changed my Apple ID password. After entering it over a 100 times on my Mac, iPhone, Apple TV and iPad I thought everything was fine. Until friends said that iMessages turned into texts/sms on my phonenumber.

I see in iMessage settings that I have four items: 1 number (with checkmark, grey) and 3 mailadresses (with checkmarks, black). Below the option "start new conversations from" has my number (in black!) with a checkmark.

There is no way I get my number back in black, so it's broadcast as a receivable iMessage number.

I disabled iMessages, I disabled iMessages in Airplane mode, in Airplane mode with wifi. I also disabled Facetime. Rebooted before enabling it. Signed out of iMessages. Force reboot. With and without doing the same on iPad. But no luck.

Though I saw on my iPhone that my iPad was able to use my phonenumber, but not the other way around.

Does anybody have any idea? I searched this forum, but I found solutions I've tried (see my actions above).