Is something going on here? Twice today when I open this site it says I'm viewing as a guest and I have to log in. Never had to do that before, it always kept me logged in. Something on my end perhaps?
Operating system updates frequently reset settings for no apparent reason. Windows Update is notorious for changing browser settings. Heck, my Phone ran a Google update last week and now I have 3 listings for every contact in my phone. Not the first time either. I had to spend two hours editing it to remove the duplicates. Similarly, you may sometimes have to reset browser settings or even specific website settings after an update. Software bugs can wreak havoc with interoperability between apps and/or OS's and apps. If you are going to do that, go ahead and clear all caches first. Might as well start fresh.
Another issue this brings up sometimes, for the same reasons, is due to different settings between network-connected devices, where updates can cause issues on other devices. Your computer has Google on it, and so does your phone. Each can affect the other. Same with multiple Windows computers in one house. I can't count how many times I've had to spend hours cleaning out my Favorites/Bookmarks folders and email after such glitches. It's also the reason I do not use any cloud storage, as that can literally triple the problem. Cloud storage is a nice idea, but implementation is far from mature. Kind of like direct injection.