Amazon has powered down its fleet of home delivery robot “Scouts” following poor feedback from customers.

The six-wheeled, cooler-size machines, designed to deliver packages to your front door, will be shelved for now, though Amazon said it may return to the project in the future.

“During our Scout limited field test, we worked to create a unique delivery experience, but learned through feedback that there were aspects of the program that weren’t meeting customers’ needs,” said Amazon spokesperson Alisa Carroll.

The company didn’t elaborate, but some observers reported that it struggled to get past obstacles on the sidewalk, such as trash or other minor debris. One Twitter user claimed to have seen a Scout drive straight through police tape and into an active crime scene.

The 400 or so Amazon employees currently working on the Scout project will be repositioned elsewhere in the company, according to a Bloomberg report.

Amazon first began field tests for Scout in 2019, on the streets around the company’s headquarters in Seattle.

The mini robo-cars were designed to cruise along the sidewalk at a walking pace, before stopping at a customer’s front door and opening its lid so the customer could reach inside and retrieve their package.

The company hoped the autonomous, battery-powered machines could reduce Amazon’s greenhouse gas emissions footprint in its delivery system.

“Scouts” would also save the company from paying delivery drivers.

Promising early tests led to Amazon expanding the bots into California, Georgia and Tennessee, and up until a few months ago, Amazon was still holding “meet-and-greets” in those states.

The Scout’s retirement follows other recent Amazon shutdowns. This week, the company said it was discontinuing its kids-focused video call device Amazon Glow. Earlier this year, the company announced it is spiking its startup telehealth service Amazon Care.