Main rig down, vintage laptop fall back.
Never, never, NEVER buy cheap (mainly Chinese origin) electronic goods from eBay. They are a false economy with vastly reduced lifespan, when compared to legit products. I can only assume they are cheap clones and/or factory rejects/contain inferior components.
I learned this lesson early on but it has reared it’s ugly head this very instance, in that I was given, & came to rely on 1 x mini USB wireless adaptor. At least I now know which chipset works with both Windows/Linux & have ordered a (kosher) replacement from Amazon UK.