Why does my steak turn out well done when the temperature probe says it's only rare?
This question is a little vague, but probably your temperature probe is lying to you, or you're not accounting for resting your meat. I would suggest a legit thermometer rather than one that gives you hints about the meat -- you'll have more control over the final product.

Temperature Guide:


Medium Rare Beef has an internal temp of 145F / 60 Celsius
Medium Beef has an internal temp of 160F / 70 Celsius
Well Done (ruined) has a temp of 170F / 75 Celsius


Remember that on resting your beef will rise roughly 10F / 12C in the middle as the heat distributes. So, if you pull the beef out at 160F / 70C, it will be well done by the time you eat it.

If you want Medium Rare, pull it out at 135F / 55C.