Getting started & navigation problems

Hello, I found an excellent scientific editor, but, unfortunately, I
immediately ran into some problems (I have Xubuntu 20.10 , and I ran
texmacs both through TeXmacs-2.1.1-x86_64-pc-linux-gnu and through
AppImage from the page https://
lists.gnu.org/archive/html/texmacs-dev/2022-09/msg00000.html):

1) At the very beginning I read in Help -> Getting started :
  Please move the cursor inside this piece of bold text. You will
observe a cyan box that appears around it
But when I hover over the bold text, the cyan frame does not appear.
It appears when I click on the text. And nothing changes in the status
bar until I click somewhere. Does it change somewhere in the settings?

2) I don't understand the navigation system. If I open several files,
then there are no tabs, the only way to switch between open files is
through the Go menu (is it possible to somehow enable tabs or at least
switch between files using hotkeys?). But the most inconvenient thing
is that if I switched to another file, then when I return, the
position where I was is not saved, and I get to the very beginning of
the file.

Sorry for so many questions at once

--
  Dmitry