Lost contents of Group Contacts

Humble apologies if question has been asked before.
Recently updated my Windows experience including Windows Mail, pleased so far, but alas when I start to type in my group contact (25 names) the group enters the To... part of the email message, I type the email message, then click send.......................nothing.
In my contacts folder I check the group and they are all there, yet when in the email message, they are not, sorry if this in mumbo jumbo, but I don't seem to be able to explain what is happening very well!
Your thoughts most appreciated.

In contact folder, what happens if you right click on your group folder and select send email from there. Does it send ok?

BrightBlessing: Cheers for your prompt response, yes is the answer it launches windows Mail, with all the group names, not the generic name of the group

Maybe create a new group folder and delete the old one and see how you go if it's not to much hassle for you.

Rather busy today, but I agree it seems the way to go, much obliged for your input.