Chosen Solution

The back of my Moto x4 is broken and I haven’t seen any original replacement for that , I want to know where I can find it or if I buy a generic one and use the original adehsive is the water resistance will still working?

Unfortunately once you break any liquid resistant phone, it’s gone for good, even if you use OEM parts and adhesives. I believe Mobile Defenders is a certified OEM retailer for Motorola. From a repair tech’s standpoint, liquid resistance really doesn’t mean much to devices. Although they claim they can be submerged in X meters of water for X amount of time, I don’t trust it.