Text lines with doublespace linebreaks are rendered in DTTG differently to DTP and other Markdown renders

When I have lines with doublespace linebreaks like here (each text line ends with two spaces!):

# Der Mond ist aufgegangen

Der Mond ist aufgegangen  
Die goldnen Sternlein prangen  
Am Himmel hell und klar  
Der Wald steht schwarz und schweiget  
Und aus den Wiesen steiget  
Der weiße Nebel wunderbar  

Wie ist die Welt so stille  
.
.
.

DTP renders them correctly (even with a linked style sheet):

while DTTG renders each line as a paragraph (with access to the same linked style sheet):

DEVONthink is using v6. DEVONthink To Go is still on v5.

On the Mac side I’m talking about DTP (V2) not DT3. Besides the doublespace standard is part of the very first Markdown implementation by Gruber and supported by Multmarkdown v5 & v6.

I assume something in the HTML layer in DTTG needs to be fixed.