Standard power MOSFETs out of Ebay are almost guaranteed fakes.
Actually, one of the first Ebay fakes I bought was exactly IRFZ44N. I paid the same as for genuine parts. Of course, free shipping was appealing. They worked, but had about four times the Rds(on), so a different MOSFET. I was able to use them in some hobby projects. The same cannot be said about many other Ebay fake semiconductors, which caused a lot of gray hair, such as fixed voltage regulators with any arbitrary printing on top, not reflecting the actual voltage.