I bought a fancy one and I hate it. Just don’t trust it. Could be our walls. The neighbour uses those tiny Neodymium magnets to locate the screws going into the studs, which is probably the cheapest solution you can buy.
I've got a cheap Amazon one and it's hit and miss. So much that I find more confidence in using a couple of small neodymium magnets glued to a piece of string to find the screws, like your neighbour.
Any recommendations for a good stud finder?