iPhone 8 Plus render
iPhone 8 Plus render shows what the new handset might look likeConceptsiPhone YouTube

Not only is Apple unsure on fitting the new iPhone with a fingerprint reader, but now insiders claim there is a "sense of panic in the air" at the California headquarters because key features of the new handset might not be ready when it goes on sale later this year.

It is claimed that Apple is struggling with the new iPhone's wireless charging feature and a new 3D sensor designed to unlock the handset with a glance of the owner's face.

According to company insiders, the issues are with the software used to run each, meaning the iPhone might go on sale with the features disabled until a software update is issued at a later date. The same thing happened with Portrait Mode on the iPhone 7 Plus in 2016, which arrived with the iOS 10.1 software update several weeks after the phone went on sale.

Quoting an anonymous source, Fast Company reports: "June was a tense month for the engineers and designers on Apple's iPhone team with 'a sense of panic in the air'...[the new iPhone] is expected to pack several new technologies that have never before been built into IPhones, and some of them are tricky to implement."

One is wireless charging which, despite being used by rivals like the Samsung Galaxy S8, is causing headaches for Apple and its new smartphone, known for now as the iPhone 8. The report adds: "The wireless charging components...are not the key issue, the source said; it's the software that's not ready for prime time."

The source went on to explain how, if Apple can't get the feature working for when the iPhone 8 goes on sale (likely in mid-September), it "might ship the first phones with inoperable wireless charging hardware, then enable the feature later on."

As for the new 3D sensor, which Bloomberg previously claimed is used to unlock the phone with facial recognition, instead of using a fingerprint, the source "says Apple has been struggling to get the sensor to work reliably. Again, the sensor hardware is not the problem, but rather the accompanying software."

This echoes concerns raised by Barron's - an investment publication - whose analysts said in a recent report: "We believe Apple's facial recognition solution should work from many angles and in low-light environments. However, it would not work without clear line of sight to the user's face. Even if this encompassed just 5% of login scenarios, it would mean that several times a day the new iPhone would perform worse at an elemental feature than older iPhones, which would risk push-back from consumers."

As for the location of the Touch ID fingerprint reader, which some claim will be missing from the new phone, the Fast Company source says that "in all likelihood" it will be embedded under the display. It isn't clear if that means at the bottom edge of the phone, or on a layer underneath the glass front and display panel.

Should it keep to its annual tradition, Apple will announce the new iPhone (and possibly updated versions of the iPhone 7 and 7 Plus) at a media event in the second week of September, before putting the phones on sale 10 days later.