I'm not sure when this happened, but if you are not logged into LinkedIn you cannot view public profiles[1] anymore UNLESS you are coming from a result in a search engine[2].
Which means if you put a link to your LinkedIn profile elsewhere on the web, you cannot guarantee that everyone can view it.
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[1] https://www.linkedin.com/in/mattowen
[2] https://www.google.co.uk/search?q=matt+owen+mbcs+citp+thirdspace+linkedin