I suppose I should've led with that. I tried these cheap SHARKK ones, this beefier iClever one, and a CHOETECH one that I had to return due to case defects.

Yes, the AC adapter does matter because it needs to produce enough voltage and amperage to enable fast charging.

Here is the adapter I bought. 24W Quick Charge 3.0, iClever BoostCube+ Qualcomm Certified QC 3.0 USB Wall Charger (Quick Charge 2.0 Compatible) with Foldable Plug for Galaxy S7/S6/Edge/Plus, Note 5/4, LG G5 V10, HTC 10 and More https://www.amazon.com/dp/B019GQ6S2C/ref=cm_sw_r_cp_api_lpFeAb1KCXMKF

I think the lightning cable is fine, but what I’m talking about is the part that plugs into the wall.