Siri frequently deletes "my info" and when I ask to remind me of something when I get home, it says it doesn't know where "home" is or who I am. Ideas??

I set up Siri with "my info" using my contact information. It worked well, reminding me of things "at home" or "at work." But every now and then when I ask to be reminded "at home" it states it doesn't know where "home" is, or who I am. I go into settings and notice that "my info" is blank. Why does it keep deleting my info??