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I would advise rendering the page under both circumstances to see what is actually happening. There could be differences in the page's Content, Titles, Headers, Internal links, etc... between the Desktop vs Mobile version even if its a responsive design. Also the Google Mobile tests only evaluate the pages from a technical & mobile friendliness perspective. It doesn't check the content.

I think that you should check is this real visit or fake one. Check HTTP access logs about such referrer and see in Analytics (or other website analytics software that you used). Also visit URL where backlink should be. Then: In case of link to hacked pages - disavow ASAP. Bad guys make backlinks to hacked webpages to get higher position in SERP. But this could change your linking profile. And in some situation you may face Penguin algo filter. In case of link to other pages and source look shady - disavow ASAP. This could be even revenge for removed hack. Also can bring Penguin. In case of link to non-existing link i.e. bot traffic - leave. This is case when bot make "fake visit" tricking Analytics to count it. And webmasters go to inspect source. This is "curiosity driven visit", but messing your Analytics statistics. In case of regular link that is relevant - keep it. Example - i have link from Pakisanian forum about people discussing something like type X vs. type Y. And someone share link from mine site explaining "here is difference between them" in article that is exactly about their discussion. So until you didn't see original source can be anything. Also please check question and answers here:  https://moz.com/community/q/is-there-value-in-disavowing-links-if-you-there-is-no-google-penalty  so disavowing isn't tool that you only use in case of penalty. You can use it even w/o penalty to make link profile clean as possible.