A:AnswerAlthough this product may and may not properly charge your device it is NOT a Qi certified product. The fact that you cannot find the product specification online only raise my suspicion that this is a shady product.
A:AnswerIt’s not a defect. The phone must be in a precise location to charge and get solid green light. A thicker case could also interfere with charging.
A:AnswerYes, I’m used it with iPhone 8, X, now using with iPhone XS and XS Max.
It going to work with any device compatible for wireless charge.
P.S. it’s not working with Apple Watch.