Thousands of Shopify users encountered issues related to logging in to the online shopping platform, impacting customers and several small businesses on Cyber Monday.

The outages peaked around 11 a.m. ET with around 4,000 outages reported. About 2,400 users reported problems at 12:37 p.m. ET, according to the outage-tracking website Downdetector.

The platform is investigating the issue, with the company urging users to access the website from any devices where they are currently logged in.

"We're aware of an issue with Admins impacting selected stores, and are working to resolve it," Shopify's support team said in an X post.

The company, in its latest update, said that some merchants may also see an issue with checkouts due to not being able to access point-of-sale systems.

Shopify was also down in the UK, as per Downdetector, with about 2,500 outages reported at its peak at 9:45 a.m. ET.

The outage coincides with Cyber Monday, the biggest online shopping day in the U.S., with strong Black Friday momentum and AI-powered shopping tools expected to drive sales.