SAN FRANCISCO — Tesla is dialing back its Full Self-Driving software, CEO Elon Musk said Sunday, after discovering software bugs in the new batch of the software beta.

The company had rolled out a new version of its driver-assistance software to an expanded group of users over the weekend, but Musk said that it proved problematic and that the company was working on fixes.

“Seeing some issues with [version] 10.3, so rolling back to 10.2 temporarily,” he wrote in a tweet. “Please note, this is to be expected with beta software. It is impossible to test all hardware configs in all conditions with internal [quality assurance], hence public beta.”

The update had already proved troublesome earlier in the weekend, as Tesla delayed its initial release Saturday morning because of what Musk wrote was “regression in some left turns at traffic lights” found by internal quality inspectors. But he said Sunday that the company has proceeded with the rollout, noting that it leans on the public to gather more data on driving conditions and parameters.

Users reported sporadic issues including hard braking events, forward collision warnings and other system misfires that had not been present in previous versions.

It was the latest twist in a saga that has disrupted typical car industry practices and drawn the attention of safety advocates and regulators, who fear the consequences of Tesla foisting the largely untested software on the public. Full Self-Driving is an expanded iteration of the software that Tesla calls Autopilot, which can navigate highways, summon and park cars, and conduct other maneuvers with an attentive driver behind the wheel. Full Self-Driving brings those capabilities to city streets, allowing the software to navigate Tesla cars through local roads and residential areas. Users must pay attention at all times, and the software — despite its name — is not considered autonomous by industry or regulatory definitions.

Tesla, which had initially provided the Full Self-Driving beta to a group of about 2,000 users, has since expanded the program using a “safety score” beta that rates owners’ driving on a zero-to-100 scale. The first rollout to around 1,000 new users included those who scored 100 in the safety assessment, which rates driver on factors such as aggressive turning and hard braking.

This weekend’s rollout included those who had scored a 99.

Meanwhile, some users on Sunday reported losing Full Self-Driving entirely after Tesla dialed back the software beta. Reports abounded on social media of users losing their features entirely instead of receiving an older version as Tesla intended.

Tesla did not immediately respond to a request for comment. The National Highway Traffic Safety Administration acknowledged a request for comment but did not immediately provide a response.

NHTSA, the country’s top auto-safety regulator, has pressed for more information on the software and says it relies on the public to provide insight into how it works. Its chief counsel sent a letter to Tesla earlier this month decrying its use of nondisclosure agreements, for example, to prevent Full Self-Driving users from sharing information on the beta.

“Despite Tesla’s characterization of FSD as 'beta’ it is capable of and is being used on public roads,” Ann Carlson, the NHTSA official, wrote. “Given that NHTSA relies on reports from consumers as an important source of information in evaluating potential safety defects, any agreement that may prevent or dissuade participants in the early access beta release program from reporting safety concerns to NHTSA is unacceptable.”

Musk has indicated users will not be bound by nondisclosure agreements going forward.