STR:
Paste the following lines in a new document.

Test
Test
Test
Test
Test

Place the caret at line 3.
View -> Hide Lines.
Place the caret at line 2.
View -> Hide Lines.
Click on the show-lines markers.
You should get this:

Click on the single show-lines marker.

Result:
NPP crashes.

Notepad++ v8.4.5 (64-bit)
Build time : Sep 16 2022 - 07:53:18
Path : C:***Notepad++ Original.exe
Command Line :
Admin mode : ON
Local Conf mode : ON
Cloud Config : OFF
OS Name : Windows 10 Pro (64-bit)
OS Version : 20H2
OS Build : 19042.985
Current ANSI codepage : 1255
Plugins :
ComparePlus (1)
HTMLTag (1.3.2)
MenuIcons (1.2.5)
PythonScript (2)
_CustomizeToolbar (4.2)