Amazon is facing technical difficulties on Prime Day for the second year in a row

AP Photo/Patrick Semansky, File

Some shoppers complained they could not add new items to their carts.

• Amazon faced technical difficulties on Monday during Prime Day.
• Customers complained that they couldn't add items to their online shopping carts due to glitches on the website.
• Amazon also faced technical difficulties online during Prime Day 2018, with experts estimating the company lost millions of dollars in sales.

For the second year in a row, Amazon is facing technical difficulties on Prime Day. 

Customers complained that they could not add anything to their carts on Amazon on Monday, during the company's 2019 Prime Day event. 

When Business Insider attempted to add items to the cart, we faced similar issues soon after 11 a.m. ET on Monday. The items were eventually added to carts after initial failure. 

Business Insider/Kate Taylor

An Amazon spokesperson did not immediately return Business Insider's request for comment. 

Amazon faced technical difficulties last year on Prime Day, as many customers struggled to make purchases. Experts estimated the company lost millions of dollars in sales due to technical difficulties in 2018. 

Amazon Prime Day 2019 kicked off on Monday and will continue into Tuesday as a massive, 48-hour shopping event. 

This story is developing and will be updated.