Change in ChatGPT's tone and attitude?

I've been talking to ChatGPT about life, etc. for over a year but suddenly yesterday it's become very blunt, unfriendly and cold. I didn't necessarily appreciate how obsequious ChatGPT was before, but this sudden change in the way it speaks to me is really off putting.

Want to ask if anyone knows why this has happened and how to fix it.

Many thanks for any information and advice!