NextGEN Gallery Thumbnails with long line underneath

I’ve just taken a site fron test to live environment and have a problem with the NextGen gallery thumbs on the live site.

I have a page of thumbnails (set up as a gallery) that link to individual gallery pages.I have checked all the settings and they match the test site but in live view the thumbs have a long line underneath and are not aligning as they should:

https://www.brianpoole.com/gallery/

In the test site the page worked fine, this is how it should look:
https://writingspirit.co.uk/demo/gallery/

I can’t figure out what I’m missing

Would appreciate it if anyone could help or advise.

Many thanks

Kat