Computer makes USB unplugged noise when I run the microwave/heater
A heater often uses almost all of the current capacity of a circuit. A microwave, unless it is some tiny little portable unit, will often use enough amperage on a circuit where it should be recommended to run the unit on its own dedicated circuit.

Considering the above it is playing a dangerous game to be running your computer on the same circuit as these other heavy load devices. Low power conditions going into the computer could wreak more havoc than simply making the USB device detection circuit get falsely triggered. You run direct risk of a glitched write to the hard drive / SSD causing the system to become unbootable. There is also a distinct possibility that power surges could cause the internal DRAM content to be compromised causing invalid data to be stored in files or causing running software to perform erratic actions or outright crash.