Hi,
syntax highlighting as described on :syntax_highlighting can suppress newline in some situations. I did not understand what triggers it.
It's easy to reproduce though.
````
begin
blah blah blah...
reblah reblah reblah
nope nope nope
end
````
The result (a screenshot of dokuwiki.org/playground) :

I guess it's an issue with highlight_lines_extra.
@schplurtz: works for me, I am on 2018-04-22 "Greebo". What version do you use?
master (dokuwiki.org) does have the issue on Chrome Windows...
@LarsGit223 Sorry, I should have mentioned the DW version.
You are right, no problem on my production server, greebo 2018-04-22c.
This happens on a clone of master.
@phy25. yes the problem is with highlight_lines_extra.
Sorry. It seems, it's not my day. I just forgot any relevant piece of information. going to bed...
Known problem. See https://github.com/GeSHi/geshi-1.0/pull/134
https://github.com/GeSHi/geshi-1.0/pull/134 has been merged, but it is still pending a GeSHi version release before DokuWiki can use it.