Sometimes people enters in the room, but it appears empty, although it is not, it is on conference with other people

It is happening often. The room appears precisely the same, but empty for a new user “You are the only one in the room”.

Another strange thing, is that the name of the meeting appears with an initial capital letter, which does not corresponds to the URL.

internally all room names are lower cased, the initial capital letter is just to make the name with the jitsi-met convention (4 unrelated words) appear more legible.
no idea about your other problem.