How this started
I was reading this (the day I posted this): How do you output a multi-line string that includes slashes and other special characters?, and when trying to bookmark it, an error appeared, "You have to be log on to vote".
What? Also, I did not accidentally press the vote button. When I pressed the bookmark button, it highlighted it in light blue.
Then I looked at the site's header, and my avatar and everything were there, but there were no Log in or Sign up buttons. That means I logged out somewhere but it wasn't reflected or updated on the website.
Then I went to the Meta Stack Exchange site. I was also logged out there.
A few things to clarify:
I didn't make any changes to the Stack Exchange network or my browser.
I will occasionally leave this computer without visiting Stack Exchange for a week or so, and no problems will occur.
Today, my ISP throttled my connection. However, today's Stack Exchange web pages loaded quickly for the most part. This isn't the cause of the misery things happening to me because I leave the computer shut down for a while and then log back in, unless some bug occurred in the timeouts of my connection.
The scary second encounter
- My connection is back to normal speed.
- The question I was on: Ubuntu 21.10 - Thunderbird 91.x.x drops (movemail) mbox support!, this time when I was there; I noticed the Log in and the Sign in buttons.
- I assumed this was limited to Ask Ubuntu, so I checked the Parenting Stack Exchange tab I had opened before the Ask Ubuntu question. I got the Join this community option there (auto updated), which means I'm logged in to the Stack Exchange network somewhere.
- Then I checked a Stack Overflow question - I was logged out.
- But I was logged in in Meta Stack Exchange site.
Third episode of this misery
Happened on Tex.SE.
This is unmistakably a bug.
Long, long time after...
This happened about three times after that, but not in the last 20 days. I was told to flag the question and add the status-review tag, which I did. I was also instructed to include any new incident information.
In December and late-November I contributed/visited SE about 20-15% of how I do normally.
debug, debug & my concerns
Support, You are awesome, however if you did respond just at the time when this started happening and promptly arranged a developer for me who may tell me what specific aspect of the website/network I need to keep an eye on, record, etc. (an insight why I request this; see the last sentence of the comment linked) then that would have been fantastic. (But I know that was a holiday season.)
User Wolgwang has also experienced this bug on the site(s) and in chat - his comments, however I don't know it is the same cause (quoted ↓) .
I had sent a message just 3 minutes ago. I was automatically signed out. I was on android device so no chance of interference by any extension. This had happened to me a few times before also when opening the SE after being offline for some time but never while sending a message.
What is the most plausible explanation for this?
My OS: Windows 7
Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.110 Safari/537.36