I lived with a buddy of mine who owned one of the first generation Keurig machines. We had problems with roaches cropping up here and there and we tried everything to get rid of them from diatomaceous earth to calling an exterminator but they always came back and we had no idea where they were coming from. We had assumed at some point that it was probably from an adjacent town home so we just dealt with them as they came and I didn't think much of them after that. Fast forward a year or so and I've moved out of the place. I get talking with my buddy about the old roach problem and he tells me that he found out where they were nesting when his Keurig machine stopped working and he attempted to open it up and they came pouring out of the machine. My buddy grabbed some roach spray we had stocked up on and drenched the machine in it to kill as many of the damn things as he could. He ended up throwing that machine away. I'm glad I switched to French press and moka pots forever ago.
Around 40% of commercial coffee makers are infested with roaches. Garbage, sewage, and waste from humans can all be fertilized by roaches, and their intestinal parasites can spread. Look for different factors to determine if your coffee maker is infiltrated by these insects. Because coffee grounds and roaches almost look like each other, it may be difficult to identify them in your coffee maker.
Yeah even the quoted paragraph is barely coherent, each sentence is only tangentially related to the others. It's like someone googled "cockroach coffee" and pasted in a sentence from each of the first 4 results... which is honestly probably not far from the truth.
I'm so glad I don't drink coffee. I think I wouldn't be able to handle a roach-infested anything in my home. At least, afaik, roaches aren't that much of a problem in Germany