The window has been scrolled left (scroll-left) for some reason.
C-x < or C-<next> can get you into this state.
C-x > or C-<prior> can get you out of this state.
Note those commands are blocked by default. When using them the first time, you will be asked, whether or not to enable them, in the minibuffer.
Note: if you press two times C-x &...
That's to be expected because this is the Emacs Lisp reference, not the Emacs manual. It explains how a developer can adjust the vertical scrolling in a fine-grained way.
Emacs 26.1 introduced pixel-scroll-mode which demonstrates this capability.
Just customize option ccm-ignored-commands, adding recenter-top-bottom to the list of commands that centered-cursor-mode lets happen without kicking in afterward.
How I found this:
I never heard of centered-cursor-mode. I followed your link, downloaded the source file, and looked through its options, to start with. Saw this option, tried it.
Just adding to answer by @jue above.
The C-x < ("scroll-left") command horizontally scrolls all text lines to the left, which means that the window's view "pans" to the right. The emacs doc section on Horizontal-Scrolling does a pretty good job of explaining.
The way to get out of this pickle is as follows:
Get back to start-of-line ...
By default, lazy highlighting is lazy. It doesn't highlight beyond what's visible or has already been visible. You want to make it highlight matches everywhere, even those not yet visible.
Try setting option lazy-highlight-buffer to t. C-h v tells us:
lazy-highlight-buffer is a variable defined in isearch.el.
Its value is nil
You can customize this ...
The O.P. has indicated in a comment underneath the question that he/she has tried (and likes) the recommended setting (also set forth in a comment) of (setq scroll-conservatively 101); and, that the O.P. prefers that the setting be global (as opposed to just buffer-local for a particular major-mode). Many examples scattered over the internet use a value in ...