- Try to find out why the traffic has stagnated - Is there a drop in the ranking?
- Revisit the old content and try to optimize it for missing keywords
- Write new content for keywords that has a medium search volume but low Keyword difficulty
Wait for a while. If the page stagnates more than 7 days look for new users by writing new content, sharing more in SM profiles and explore A/B testing. Also look for the topics that were before popular and try with them but giving now different approach. Deep down into SEO with some tools like Spark Toro or Semrush and try to see what content your target groups are now searching and reading.