If the filter elements rattle then they were defective parts bough as scrap the on sold as good products.
I have been buying my filters direct from China in 100 lots ( MOQ ) from the factory and never ever had a problem
Probably fitted around 1000 by now . The last batch were around 25¢ each including post to Australia appear to be identical to the $ 2.75 ones from my suppliers an the $6.50 retail ones .
So I charge $ 3.00 & customers think I am santa clause. When I charged $ 1 they complained that they did not want any of those cheap filters , so I put the price up
People are funny some times .
Scamazon & evil pay were specifically designed so the vendor could hide their identity because they were made by criminals for criminals to use .
I usually buy fro Alibaba or made in china
Both are B 2 B so I know who I am dealing with and the only time I have had any problems ( apart from a couple of incorrect descriptions ) was 3 or 4 times the packaging was not up to scratch and the parts broke . In both cases I got full refunds & kept the parts
Funny how Americans are cheats and Chinese are honest