So then it's just a coincident that my old WIFI adapter and my new WIFI adapter also broke at the same time.
Not very likely but possible. HWiNFO is software and software readings of voltages are not that accurate and reliable.
But you said you tested with a multimeter and voltages were OK. If other USB devices such as USB flash drives work properly and don't get "hot" in any of the back or front USB ports I think it's probably the WiFi adapter/dongle itself at fault. If both were the same brand and model it's more probable, maybe a faulty design or bad quality or just sheer bad luck.
Also I asked you in post #14 if the WiFi adapter/dongle works or not and you didn't explicitly answer that. Now you say both broke. If by "broke" you mean it's faulty/not working chances are there are issues like a short circuit inside the adapter/dongle or other faulty parts like the controller chips and antenna components that make it run hot.
Is the PSU to blame for them failing, maybe, maybe not. However, it's actually the motherboard that (via controller chips) controls and runs the USB ports and connected devices and gives them power. You mentioned "not known brand", do you mean the PSU or the WiFi adapter/dongle? If the PSU is not a good quality I'd suggest you get a good quality unit which is adequate for your setup. So what are you full specs including the make and model of PSU?
As I said in post #4 it's probably the USB adapter/dongle that's faulty here and the problem is probably not caused by the motherboard/PSU/port.