Syntax highlight getting lost when jumping down large file

I am writing a book using Asciidoc format. You can find the Asciidoc file here:https://github.com/krlawrence/graph/tree/master/book

I am using MacVim version: 8.0.1420

I have not noticed this problem as much in earlier versions of MacVim and it is not an issue editing the same file on Windows using Gvim.

If I load the file and set the syntax to Asciidoc the highlighting looks fine. However if I then do a search that requires jumping way down the file or if I just manually jump to the end of the file, syntax highlighting is lost. Doing a syntax sync fromstart does not bring it back and setting the syntax back to Asciidoc again only seems to work if I jump back to the top of the file and manually scroll down the file. As soon as I jump down the file again same problem. This seems to have started happening since I updated to this version of MacVim.

My OS is MacOS 10.13.3

I have sometimes seen this behaviour before but never until now encountered a case where doing a syntax sync fromstart does not fix it.

Inizia riproducendo il report con il file Asciidoc nella directory del libro collegata, usando MacVim 8.0.1420 su macOS. Confronta l’evidenziazione della sintassi dopo aver caricato Asciidoc, essere saltato alla fine, aver eseguito syntax sync fromstart e aver fatto scorrere il testo dall’inizio. L’attività è completata quando l’evidenziazione rimane corretta dopo grandi spostamenti e il comando di sincronizzazione segnalato funziona come previsto.