What happened

Apple (AAPL -1.22%) wasn't necessarily a fresh and healthy stock at the end of this trading week. Its price declined by nearly 2% on Friday, which was notable for being the first day of preorders for the company's just-introduced iPhone 13 models.

So what

The phones, which were introduced in the latest of Apple's long series of "events" earlier in the week, apparently weren't as available as intended. According to a report on CNBC published Friday morning, several holders of the company's Apple Card had difficulties with their iPhone 13 orders -- so much so that "Apple Card" became one of the top trending phrases on Twitter.

Two women, one with a smartphone, seated at a table and talking.

Image source: Getty Images.

One Twitter user, @carlosocean_com, tweeted that he had a "Terrible experience while going [through] the iPhone upgrade checkout process" and added: "Apple Card was not working. In the iOS app I was able to see the error, on the website, just an infinite loop on place your order page."

The typically tight-lipped Apple did not respond to CNBC's request for comment, nor did it issue an official statement on the situation. In the morning, a message on the tech company's system status page read "Some Apple Card customers are not able to make iPhone Upgrade Program purchases." As of late afternoon, Apple Card's status read "Apple Card-Resolved Issue." It's not clear what the problem might have been.

Now what

Anyone who has been around tech product launches knows that it's rare for the process to go perfectly smoothly.

It's a bit troubling that Apple had difficulties in this instance with Apple Card holders, who tend to be loyal fans of the company's products. However, as long as the issue's apparent resolution sticks, both investors and clients will probably get over it quickly and enjoy the benefits -- either as shareholders or users, or both -- of the new phones.