Yoast page title not working as it should

Hi People.

Please can someone help with a problem that I am having with the Yoast plugin that is really frustrating me.

My title tag is too long because the Yoast plugin includes the site name and page title together. This is making my title appear to long. When I do a free SEO report for my domain https://www.computerwised.com I get the following output.

Title Tag:

Computer Repairs Basingstoke, Laptop Repairs Basingstoke & IT Services – Computer repairs Basingstoke, Laptop Repairs & PC Repairs Basingstoke

How do I set Yoast up to exclude the site name in the title tag. Presumably this is something that will help me rank better?

Many thanks