Why are my SMS messaging groups disappearing?

[philsnelman]

I have created several SMS messaging groups on my Lumia 550 phone running Windows 10 mobile. The problem is that they keep disappearing! I have re created them several times but after a day or two, they're gone! It's driving me crazy! Can anyone help me or is this a bug?

 

[Chintan Gohel]

How did you create the sms messagin group? Is it by creating a new sms and then adding many contacts?