The social media site updated their app on Thursday and users weren't too happy.
The bug led to a small test being distributed widely, the company said.
If you opened up Instagram today, you may have been surprised to find that the vertical scrolling method of browsing content had been replaced with a completely different horizontal tap-based scroll.More news: Mahomes sets Chiefs' single-season passing yards record
'Introducing a new way to move through posts, ' a pop-up told them.
Mosseri confirmed that the update should be cleared for everyone, and to just restart your app if you were still seeing it.
Regardless, with such a considerable change, many users have taken to Twitter to express their disapproval of the Instagram update, as well as appreciation for the quick turnaround. Our redesigned algorithmic Friend Feed made it harder to find the right people to talk to, and moving too quickly meant that we didn't have time to optimize the Friend Feed for fast performance.More news: US oil prices extend gains as equities rise, but economic worries weigh
Typically, an Instagram feed goes up and down, with a user able to flick their finger through a number of photos. "We apologize for any confusion", a representative said.
Minutes after the update went through on many phones, some noted that their app reverted back to infinite scroll and the update appeared to have been removed.
You now click through posts in a similar way to how Instagram Stories have previously worked, rather than the traditional up-and-down swiping movement. In effect, the entire feed turned into a Story, with tap controls as well as a progress bar up top.More news: Pep Guardiola calls for Manchester City calm ahead of Leicester trip