Apple’s long-awaited overhaul of Siri has hit another stumbling block, with reports suggesting key AI features may be delayed beyond the upcoming iOS 26.4 release.

The tech giant had been targeting March for the debut of its upgraded voice assistant, tying the launch to iOS 26.4.

However, internal testing has reportedly uncovered performance and reliability issues, prompting Apple to consider pushing some features to iOS 26.5 in May, or even to iOS 27, expected in September.

According to Bloomberg, engineers have encountered problems including Siri failing to consistently process queries, slow response times and accuracy issues.

Testers have also reported a bug that causes Siri to cut users off if they speak too quickly, as well as difficulties handling more complex, multi-step requests.

One of the most anticipated additions, expanded personal context awareness, appears especially vulnerable to delay.

The feature is designed to let Siri tap into on-device data, such as searching old Messages conversations to find a shared podcast and play it instantly. Apple is said to be trialling the capability in later builds of iOS 26.5, with some versions including a “preview” toggle that suggests it could launch in beta form.

The revamped Siri is built on a new internal architecture known as “Linwood” and powered by Apple’s Foundation Models, incorporating technology from Google’s Gemini.

However, reports indicate the system can sometimes default to its existing ChatGPT integration instead of Apple’s own AI, even when it should not.

Other delayed features include advanced “App Intents”, which would allow users to perform multi-step actions – such as finding, editing and sending a photo – using a single voice command.

Despite the setbacks, Apple is continuing development on additional AI tools, including a web search feature similar to Perplexity and an image generation tool powered by the same engine behind Image Playground.