I am having the same issue with that same probe on the brew boiler. Most of the replies to this thread have been assuming we're talking about the steam boiler probes.

My right probe on the brew boiler comes out fine but the left one has the exact same problem you describe. I have a feeling the plastic is deformed and will not budge through the hole because I noticed a little deforming on the right probe even though I was able to pull it out.

For those with the same issue. This is why the probe was getting stuck and wouldn't come out. You can see where the plastic melted/deformed at the bottom. It took a lot of pulling and twisting to finally get it out. Luckily I found a place that had replacements in stock before I went this far with it.