Strange Transactions

I put in a limit order for a certain stock at 55 and for some strange odd reason it executed at the end of the date beyond at a price of 56.85 when I didn’t even make the order. What is going on with this? I also canceled the order but yet it still executed. So it buys at a price higher than what I specified and buys when the order is canceled. Seems like there are some glitches within the Alpaca system? I can easily provide a screenshot of the order being canceled and at a lower price than what was executed.