According to The Verge users are experiencing a "static" or "crackling" sound when they make calls and are using the earpieces.
Citi suggested that sales will be lower during the fiscal fourth quarter as customers wait for the iPhone X to release in November before making a purchase decision. It also has a new glass finish and is the first iPhone to support wireless charging.
Most industry watchers say Apple's problems aren't necessarily a big concern for the company.
Apple will likely save its flashy new features for the next major software releases, likely to be 11.1 sometime later this year. With the new system, users can access immediate 911 calling by either pressing and holding the side button on an iPhone 8, or tapping the power button five times on older models.
The battery on the iPhone X is slightly larger than the one found on the iPhone 8 Plus, standing at 2,716mAh compared to 2,691mAh, respectively. On the Tom's Guide Battery Test, which involves continuous web surfing over LTE, the iPhone 8 Plus lasted a very good 11 hours and 16 minutes. And Apple started fixing things with this minor update. With iOS 11 installed, this number plummets to just 96 minutes - over twice as fast.