SIRI won't send text message to one of my contacts

This is a bit of an odd one.

I often send text messages using SIRI. It's always worked fine until this weekend. To my knowledge nothing has changed in my contacts. But now just one of my contacts no longer works when I try and text with SIRI. The same is true with asking to call this mobile number too.

I can call, iMessage and text manually OK (this contact has an iPhone 4).
But if I use SIRI 'he' just asks which email address I'd like to use or says that this contact has no mobile number. Even if I explicitly say send a text message to........ only email options are given.

With all the other contacts I've tried it works fine.

I've compared this contact with others and can see no obvious difference.

I've deleted and re-added the mobile number but no change.

I've added a dummy contact with a different name but the same mobile (just for debug purposes) and that works.

I'm wanting to just put this down to a beta bug but it's odd it's worked for so long.

Any thoughts?

what's the name? because if it's hard for her to understand then that's obviously a problem....I'd suggest renaming the contact a sort of shortened verion or a nickname of the person instead and see how that does. It has nothing to do with their number obviously that name messes her up.

Thanks. But it's not the name.

SIRI recognises the contacts name no problem and offers up a choice of emails to send an email to rather than a text. Or says "Fred does not have a mobile number "

What is the "category" of the number in the contacts list? I'm wondering if it is under something other than mobile or iPhone?

I'm just putting out ideas, I don't use Siri that much so not sure what the cause would be.

Thanks for the replies.

I've tried mobile and iPhone and both but it behaves the same for all

After much trial and error I have found a solution.

The contact was unified from two entries. I disconnected them then re-unified them and it now works fine.

Still no clue as to why it stopped working to start with.

That's a curious bug you've found. You should most definitely report that to Apple.

Already done
But it is odd. Got a dozen or so unified contacts that still worked.