ChatGPT providing broken links as a source

Why has ChatGPT been providing broken links as a source since last week?
Is there a way to compel him to provide the relevant source link? When I tried to ask the Chat, the answer was that the information was updated to the end of 2023, but it worked until two weeks ago.

Welcome to the forum.

Without seeing more details such as the prompt, the reply, checking the supplied links and know valid links the best I can offer is that some links may be hallucinations.