There are a series of things that can be wrong both with the hardware you plug in and with the plug itself. Things can straight up be wired in the wrong order,

There are a series of things that can be wrong both with the hardware you plug in and with the plug itself. Things can straight up be wired in the wrong order, grounding can be done incorrectly so there's more than one path to ground which among other things causes there to be a voltage difference between the neutral wire and the ground wire, corrosion or bad connections can cause similar issues. The first cheap test you can do is buy one of these plug testers that diagnose some of the more direct problems you could be having for about £10, don't necessarily buy the one I linked, but do a little research and pick something that seems right. https://www.amazon.co.uk/QUILLE-Socket-Display-Neutral-Testing/dp/B07GNPKHQ9 https://www.amazon.co.uk/QUILLE-Socket-Display-Neutral-Testi... If you're having those kinds of problems, it wouldn't hurt to contact a local electrician and quickly describe the issue and ask what it would cost to diagnose.