Jason, take a deep breath and relax. There's a good chance the probe is in a fat seam, stuck too far into the meat, could be a probe gone bad, etc. Meat hasn't started suddenly cooking/smoking differently just because we've added all this technology to the process.
I've stopped using my meat probes. They were causing me more headaches, like yours, than they were giving me confidence. After a few smokes that turned out less than desirable, I pegged the problem to technology. Now I let the meat and smoker do their thing, and I'll use an instant read that I know is accurate to check the progress. If you have one, start checking the temp in several places, but also pay attention to how the probe feels when it goes into the meat, especially a flat on a brisket. A point will probe butter soft WAY before the flat due to all the fat, but that doesn't mean it is done.
Not using a meat probe is kind of old school, but my headaches went away and the results are once again consistent. Sometimes the old ways are the best ways.