I set up a waypoint mission at the beach to catch the sunset, with one shot at about 20-30 feet above the water. I ran the mission a few hours later (yes, I know tides change) but I also took off from about 10' higher than when I set the waypoint. The low shot was set at a point I had been shooting for years and had never had an issue with water coming near it, waves and all and the waves were not large this day.
So it descends to the low shot and keeps going down into the water as I frantically try to use the joystick and bring it up. I could only watch in horror as it sunk and lost transmission.

Anyone else have this issue?

Hi, Straker. Thanks for reaching out! We're sorry to read about your truly unfortunate experience. There are many factors that might cause or possibly caused the said flight accident. Our suggestion, we recommend getting in touch with our Customer Support to assist you to open a ticket if you're within the warranty period. Hopefully, this can be sorted out immediately and provide enlightenment as to what happened.

Did you try pressing the Cancel button (RTH)? It should stop the aircraft from doing whatever it is doing, in this case a hyperlapse mission, and allow you to take manual control with the sticks.