We've recently re-done one of our websites around 3-4 months ago. Depending on what your searching for, google will show the correct title or the wrong title. For example: When searching for our parent company, google will show the name of that company above our website. When searching for our actual company name, google will show the correct title. I've submitted a sitemap and had google fetch pages but nothing seems to work.
You need to collect a list of these occurrences and find a common cause or pattern and present them.
Your current post is not enough information for other people it's just flying blind.
Check how your theme structures urls.
For bad titles check those objects(products,pages) seo section at the bottom of it's admin page.
Or hire an expert to dig in for you.
Please find the below reply
Google's generation of page titles and descriptions (or "snippets") is completely automated and takes into account both the content of a page as well as references to it that appear on the web. The goal of the snippet and title is to best represent and describe each result and explain how it relates to the user's query.
Google uses a number of different sources for this information, including descriptive information in the title and meta tags for each page. So if Google thinks that your given title is related to query then it will show on Google.
You can try to fetch your page by using google webmaster tools, but before that, please check robots file and meta.
Hope this will work if google thinks that your title is related as per query.
Thanks & Regards
MS Web Designer Team
Official Shopify Expert and Partner