Gibberish at end of URLs

Hello all. I’ve just noticed some odd and a bit annoying on my website, and I wonder if anyone can help me to fix it.

In the footer, on the right, I have three links (about, Product Info and Contact). For some reason that I am unable to work out, these three links (and apparently only these three links – the others are all fine) have a lot of gibberish at the end of the URL. This has been added to the end of the slug I created for each page.

I asked this question on the wordpress forum, and a kind person told me this:

“The parameters behind the URL come from the Google Tag Manager integration in your website. Since you are using the Google Sitekit plugin for this, I would recommend that you contact their support forum for clarification”

I’d be so grateful for any clues about how to fix this. Thanks

The page I need help with: [log in to see the link]

 

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