On Tuesday, AT&T wireless service went down for some customers, affecting their ability to contact 911 in the event of an emergency.

It was fixed in a few hours, with the company blaming a software issue, but it’s just one of many problems the telecommunications company has faced over the past several months, including outages and data breaches that have hampered its operations and left users in the lurch.

In February its network went down for 11 hours, preventing many of its customers across the United States from placing calls, texting or accessing the internet. AT&T said an initial review of the outage found it may have been caused by an error within the company and not a cyberattack.

A few weeks later in March, a data leak that included personal information of 73 million current and former customers was released into the “dark web,” sparking security concerns. The data came from 2019 or earlier and did not appear to contain financial information or specifics about call history, the company said. “It is not yet known whether the data … originated from AT&T or one of its vendors,” the company said at the time.

Then, in June, another AT&T outage prevented some customers from completing calls between carriers. The issue was solved within a few hours, but the company didn’t reveal what caused the issue.

And a security nightmare was revealed last month when the call and text message records from mid-to-late 2022 of tens of millions of AT&T cellphone customers and many non-AT&T customers were exposed in a massive data breach.

Compromised data included the telephone numbers of “nearly all” of its cellular customers and the customers of wireless providers that used its network between May 1, 2022 and October 31, 2022.

Notably, Tuesday’s outage came just hours after the Federal Communications Commission announced a $950,000 settlement with AT&T to resolve an investigation into whether or not the company violated FCC rules by failing to deliver 911 calls and timely notify 911 call centers during a previous outage in August 2023.

AT&T’s overload

So, why does this keep happening to AT&T? One telecommunications expert with whom CNN spoke believes it’s a combination of three issues, including overloaded networks in major cities, software updates that have gone haywire and various technical problems.

On Tuesday, an outage map showed disruptions in New York; Charlotte, North Carolina; Houston and Chicago. Alex Besen, founder and CEO of Besen Group, which analyzes mobile phone companies, said that led him believe it was a network overload issue.

“To avoid any future outages, AT&T needs to increase the number of cell towers, implement advanced load-balancing techniques, use network optimization tools to manage traffic more effectively and prioritize services that can reduce congestion,” Besen told CNN.

Ari Lightman, professor of digital media and marketing at Carnegie Mellon University’s Heinz College, said AT&T’s response about Tuesday’s outage being a software issue left it “unclear if that is on the implementation side or a bug in the code.”

“Customers are becoming increasingly frustrated with AT&T for repeated outages and customer service leaving the issue unresolved as they await critical updates,” Lightman told CNN.

He added that, in AT&T’s defense, it’s “also important to note the complexity of the network infrastructure to service 115 million wireless subs as well as their aggressive rollout plans of new networks.”

“Our customers expect and deserve reliable connectivity,” an AT&T spokesperson said in a statement to CNN. “When service disruptions occur, our team of network experts work to restore service as quickly as possible. We value our customers and keeping them connected is our top priority.”

This story has been updated with additional developments and context.