According to https://lestat.org/, the Blåhaj instance is down notably more often. What is happening or causing this?
Is it server costs? If so, I’m willing to contribute, but how should I do so? And if not, what would it be? Host issues? Targeted attacks, perhaps?


Depends on your timezone.
Comparing Sydney, London, and San Francisco, it’d be around 17 o’ clock in Sydney, then it’s 8 in London and 0 in San Francisco.
That is how time zones work. I have left it as an exercise to the reader to determine the likely time zone I am in.