Prolific question

I have been using Prolific for a few weeks and it has paid for better than I ever could've imagined. One day, I was away from home and used my hotspot to access Prolific. I had 30 studies available but when I reconnected to my home wifi, I had no studies. If I use my hotspot, I always have 20 or more but zero if I use my wifi. What's the reason for this?