Your LinkedIn profile and your CV do related but different jobs. Copying one into the other wastes both.
Audience and intent differ
A CV targets a specific role for a specific reader. LinkedIn is a standing shopfront seen by many people for many reasons.
Voice
LinkedIn can be written in the first person and a little warmer; a CV stays concise and more formal.
The headline and About do the heavy lifting
On LinkedIn, your headline and About section are prime real estate - make them clear and searchable, not just a job title.
Keep them consistent, not identical
Facts - dates, titles - should match. The framing and depth can differ to suit each medium.
Both should be searchable
Recruiters search LinkedIn by keyword too. Relevant terms, used honestly, help you be found.