Why does my spouse keep getting signed out of Family Sharing?

I will get a notification that my spouse has left Family Sharing and 'you will no longer have access to purchases made by' my spouse. Neither of us was even using our iPhone either time. We had recently had to call technical support to request a refund for something, but no other contact with them. When this happened a week ago, I sent a new invitation and we signed my spouse up again, but now it happened again. It's starting to get annoying.