@Ernest Bywater
One of these changes may be what's causing the issues being reported.
It may account for some of them, but certainly not all, and in particular not what I observed. I think I remember I was hit by the logout of browser widely reported, but also, I have a script which saves an entire story using wget, so I have control of the cookies and any upgrades. On the morning of the 29th this script was being called in a loop (downloading some stories from a queue of stories I want downloading) and had worked through a few already (this being about 2 hours after the previous days login had expired, so well away from any site login time thresholds). At 2020-05-29t08:30:17BST (by my computer) it started on the next story and successfully saved the first page (this was a three page, single chapter story; #11280). The next page saved should have been from the story, but was actually the SOL login page (which showed a timestamp of 08:30:16, so my computer time is slightly out relative to SOLs); the subsequent pages saved were the logged-out sample of that story, and the story info file which showed I was not logged in (it had a Log In link rather than a Sign Out one). Subsequent stories downloaded in that batch also only saved the logged-out samples, and when I looked at it, the cookie file had only a single (logged out) cookie. Since wget only updates cookies on instruction from the site (when allowed, as I had, it will update the cookies after saving the file), this shows that it was definitely the site that cleared the cookies and logged me out (the only other way to change wget's cookies is to manually edit them). What I guess happened is that the hosting VM had a glitch in its clock so that all cookies were expired for anybody who accessed the site during that time; if the glitched time was beyond 2030, the 'sticky' login would expire, and beyond 2031 all cookies would be lost due to standard cookie expiry rules as implemented in all browsers. That's the most likely explanation I can conceive that fits both the 'no site changes to login code' and the widespread 'logged out and cookies cleared' experience, and not something Lazeez can influence or easily detect.