I wonder if you are also seeing this small but annoying bug in the RapidWeaver editor? It happens in the html and markdown editors when text fills a line from left to right. See pictures below.
If my cursor is all the way to the left, then the last character on the right end is cut off.
If my cursor is all the way to the right, then the last character on the left end is cut off.
Its a small problem but it is distracting.
I’m using a MacBook Air (13 in 2017) OSX High Sierra 10.13.5, RapidWeaver 8.6.2