I've purchased so many different things over the years it's hard to say which ones were bad purchases and which ones should have been good products, but simply aren't.
My current Pixel 4 XL would be one of those. It should be good, great even. It isn't. At all. Glass back makes the phone slippery as hell and gestures don't work with a damn with a case on. At $900 it should have been great.
I have a $200 speedometer calibrator that won't program my truck, that's annoying, but I haven't had time to call customer support yet.
My office receiver was a victim of the Onkyo HDMI issue, but it got fixed for free, but for years I was pissed at the HDMI acting up, but it wasn't horrible, just irritating. Been perfect since I got it back 4 years ago.
I bought a jeep compass that was a POS, but not the same topic.
My PC motherboard has a USB bug that just happens to ONLY affect people with my VERY specific configuration. Of course I'm one that has issues.
Other than that I try to make few purchases on a whim. I research EVERYTHING to death. Having sold electronics helped too since I got to see so many early products that were terrible. Early adopters are beta testers that have to pay. No thanks.