Sites stealing my page titles

Does this affect my SERP position?

[jino]

I am noticing a lot of sites stealing my page titles for numerous keywords.

For example, I have a product page with the page title widgetA from example.com

When I come across my competitor's page, they put in
widgetA from example.
without the com into the text of their page. There is no link in the text.

I used to rank highly for widgetA and now I dont at all and my competitor is in the top 5 position.

They also steal from other top ranking sites. I assume they get the data from the Google search API.
Anyone else noticed this?