It seems that the adjustments made to your title had an unexpected impact on the ranking of your main keyword. Here are a few things to consider:

Keyword Placement: Moving the main keyword to the end of the title might have altered the perceived importance of the main keyword to search engines. Titles are crucial for SEO, and the position of keywords within them can influence ranking.

Give it Time: SEO changes may take some time to reflect in rankings. Allow search engines to crawl and index your updated content before expecting significant shifts.