hi Ank,
this still happens to me with all my mc servers.
it seems while booting so many lines are generated in the webui console it locks up the browser somehow.
so what i do is select the server and press the start button then log out. wait a while and log back in. this works ok if the server has no issues.
it is a pain if the server hangs or fails to boot because you don’t know it.
i am confused why others do not report this problem and i had a thread opened myself asking, in the past. the solution offered did not work for me because i was to scared to try it, but might for you.
good luck!
tNt