A website can wipe itself from history? That seems like a major security issue.
Do you mean something you verified is happening or something you assumed is happening? You can go look at the site OP linked and find out what is happening and if it's a "major security issue". In this case, after user click/intervention, it renames the current history entry to "New Tab". This is not a security issue at all.
This is known and commonly used -- since 1996. What's the risk? You can't change records about other domains.
"I did my best" is no excuse for this critical failure to deliver as advertised.
This fail is a horrifying abuse facilitator.
Not what I asked but I'm glad you're doing okay! I share your concerns.