I waited for the issue to reoccur so I could test that out. The jwt cookie is missing from the request to / but is present in several of the other resources used for the page. That's consistent with Crashdoom's comment. Sometimes, the issue would only occur in a specific tab (refreshing the tab did nothing, but opening a new tab would have me logged in), which is roughly the opposite of what that user reported, but this time, it was a problem in any tab