Map Pack Ranking Dropped After Website Optimization. Why?

Hey everyone, I’m running into an issue with a client and could use some insight. After the recent Google Business Profile updates, our client’s local map pack ranking was holding steady at #4 for their main keyword.

We then went in and optimized their website, nothing crazy, mostly on-page SEO improvements like keyword-targeted title tags, improved title tags/meta descriptions and added service pages/location pages.

Now their local ranking has dropped to position 10+ in the map pack for that same keyword.

Their GBP hasn’t changed, NAP is consistent across the site and listings, and reviews/engagement are stable.

Has anyone experienced a dip like this after improving the website? Could there be a temporary reindexing hiccup or did we over-optimize something that triggered a relevance or proximity change?

Any insights or similar experiences would be hugely appreciated