The only thing a radio announcer and voice actor have in common is they both sit or stand in front of a microphone. However, they are two entirely separate deliveries.
When I got started in voiceovers decades ago, every script read sounded like I was doing an urgent weather update. I spent five years in radio and was groomed to sound like that. It took several months of coaching to break from the punchy "announcer" read. Another reason coaching is so important. Just because you've had several years of radio experience, it doesn't mean you're ready for a voiceover career. Forget all you learned in radio and start over by hiring a VO coach. Having the chops is one thing, but it's the acting that gets you hired.
A few years back, I had the pleasure of coaching a long-time radio announcer for an AM news station in town. He was a great announcer and was pretty passionate about learning voiceover. But imagine trying to read a commercial script and making it sound genuine after 30 years of reporting the news. That is a tall order! It took over a year for him to lose that announcer-like delivery. You can't read a coffee commercial and have it sound like there's a tornado warning.
After a year of script performance coaching, he found his groove as a voice actor. After that, you could no longer tell that he spent 30 years reading the news. Dedication and patience at their finest. He worked his tail off until he got rid of the radio announcer-like delivery.