So, to reproduce it, visit any page on help.evernote.com once with parameter "layout=tight". My browser history tells me that in my case, that cookie came from this link: https://help.evernote.com/hc/en-us/articles/218038988?utm_source=evernote_app&utm_medium=windows&utm_campaign=v6_new&layout=tight (which, according to its UTM parameters, was opened by the Windows app).
After you have visited such a page which had "layout=tight" in the URL, you will have the cookie set, and then you should be able to reproduce my problem on the "new support ticket" page https://help.evernote.com/hc/en-us/requests/new
(Summary of the bug: After the Windows app [or possibly something else] opened some kind of help page with the parameter "layout=tight" in the URL, it is no longer possible to open support tickets in the browser until clearing cookies.)
One a side note, I discovered two small other things right now: 1) On help.evernote.com, when logged in, you see "sign out" in the top navbar, but "sign up / login" in the footer, as if you were not logged in - kinda confusing. 2) When pasting a link from the clipbaord here into the discussion forum, its text gets unnecessarily HTML-escaped, which becomes visible with the ampersands. Try it, copy "http://example.com/?a=b&c=d" (from another application as plaintext, not from here because then it's copied as formatted text) and paste it here, and it will become http://example.com/?a=b&c=d (notice the incorrect "&" instead of "&").