The U.S. Federal Trade Commission (FTC) is attempting to get to the bottom of an age-old problem — why it seems like McDonald's ice cream machines are never working. 

The Wall Street Journal reports that the agency has launched an investigation into the problem, which has become synonymous with the fast-food chain for years. The FTC sent letters to McDonald's owners, asking for details on reported issues with their ice cream machines.

While the chain restaurant placed blame on costly repairs and technical malfunctions, the manufacturer said that's not true. Taylor Commercial Foodservice LLC said the misinformation stems from a "lack of knowledge about the equipment and how they operate in the restaurants."

“[When working with dairy products] you have to make sure the machine is cleaned properly. The machines are built up with a lot of interconnecting parts that have to operate in a complex environment and manner,” a representative for the company said.

The ice cream machines are primarily used to create soft-serve cones, milkshakes and their signature McFlurry. However, customers have taken issue with the machines routinely being out of service, as well as with being unable to purchase their requested items.

Twitter user @SpookySeezn tweeted, "That was real McFunny now go McFix your soft serve machines," while Gerardo J.R Andrade tweeted, "I like how McDonald's owns the fact that they're shit."

An online track called McBroken was even created to track the outages across the United States. Additionally, customers created petitions demanding the problem be resolved.

In 2020, McDonald's addressed the common frustration by making a joke out of it:

we have a joke about our soft serve machine but we're worried it won't work

— McDonald’s (@McDonalds) August 11, 2020

"We have a joke about our soft serve machine but we're worried it won't work," the company's Twitter page tweeted.

Despite making a joke out of the situation last summer, the fast-food chain told The Hill that it recognizes its customers' frustrations and has assembled a team to address the problem. 

A customer survey by a research firm revealed that McDonald's popular dairy menu items account for roughly 60% of their dessert sales in the country. 

Now, after years of complaints, the FTC is demanding transparency from the supplier, according to The Wall Street Journal. The publication also reported that the agency is looking into whether employees at McDonald's are even allowed to work on the machines. 

When contacted by The Hill, the FTC declined to confirm whether there's an ongoing investigation into the problem. McDonald's USA said that it had "no reason to believe we are the focus of an FTC investigation." 

“Nothing is more important to us than delivering on our high standards for food quality and safety, which is why we work with fully vetted partners that can reliably provide safe solutions at scale,” McDonald’s said.