Hi Green_Web,
It looks like you have the same default title tag for all of your blog posts. The main pages on the site look like they have more suitable title tags.
The blog section looks like it's in WordPress and has a default title tag in place, which hopefully is not hardcoded into the post template.
If you don't have access or have the ability to edit titles, I would suggest talking to the devs and get them to use the post name in the title, but ideally, you would be able to independently modify all page titles through a plugin like Yoast.
The reason you may be seeing a more suitable title tag sometimes is that Google won't always use your specified title tag in SERPs - it can sometimes use your h1 heading (for example) if it thinks that is more relevant to the user's search query.
Cheers,
David