Apple and O2 have confirmed that one of the most popular iPhones is not working as it should on O2's network.
The iPhone XR completely lost signal several times a day, some O2 customers said on Twitter.
Many customers have been unable to make and receive calls or send and receive texts.
They have also struggled to get a reliable 4G internet connection, making apps such as Facebook and Instagram redundant unless there is wi-fi.
"We're working closely with our partners to resolve an intermittent issue affecting some of our customers using iPhone XR," an O2 spokeswoman told the BBC.
"We thank any customers affected for their patience."
O2 declined to say exactly how many users were affected by the issue.
Turning the phone off and on again temporarily fixed the problem, O2 said.
Apple said the issue will be resolved in a new software release.
"We are aware of an issue causing intermittent network connectivity effecting some O2 customers, and we will have a fix in an upcoming software release," the company said.
O2 customer Jim Buckley told BBC News he had first noticed a network issue on 16 December.
"I've had virtually no signal at all since," he said.
"It may come with a weak signal for a few minutes once or twice a day then go again."
Mr Buckley said he had resorted to buying a second-hand iPhone 7 for £180 as his son had special needs and he needed to be contactable in case of an emergency at school.
He said O2 had told him Apple had introduced the issue with a recent update to the iPhone's iOS software.
BBC News is waiting for O2 to confirm if this is the case.
Mr Buckley added O2 had offered him a month's free line rental as compensation.
O2 and Apple are telling customers seeking answers on Twitter to direct message them.[NewsNaira]
Share this article!
Others are also reading
Feminist Techie Develops Plugin That Auto-Deletes Unsolicited Nude Photos From Twitter DMs Read More2 days ago
What is News₦aira Income Program(News₦IP)
News₦aira Income Program (News₦IP) is a system aimed at raising revenue for registered users that browse the NewsNaira Website. An online program driven by a goal of solving the financial problems among the youths, students, middle class and whoever wishes to take advantage of earning opportunity and making money online legitimately in Nigeria as it creates the channel for participants to earn residual income on weekly basis.
How News₦IP Works
News₦aira has 2 means of generating income for our members.
News₦AP: NewsNaira Affiliate Program - With News₦AP, participants earns ₦1,000 whenever they refer anyone to join NewsNaira Income Program. There is no limit to how many people you can refer.
News₦ARS: NewsNaira Ad Revenue Sharing - With News₦ARS, participants earns residual income bonus by reading news, commentting on articles, publishing forum posts, daily login to their NewsNaira account, and even sharing assigned sponsored post on social media.
We share our ads revenue with you weekly when you make NewsNaira community your news and information household.