TOPIC: Required field does not update correctly on Chrome

Every month we have a few member records which do not have any of the three radio buttons checked, although they have checked one upon registration.
This custom field is required, however. It shows like that on the form.

Dinner Choice June 2016: *
Parmesan Encrusted Chicken Breast
Stuffed Salmon Roulade
Vegetable Lasagna


Do you have any idea on how to fix this? It looks like it is always Chrome that has the issue.

Thanks a lot,
Olympia