Copy/paste from list creates unexpected newline

[smltr]

Hope you don't mind opening issues, I have found the app useful when I'm wanting to jot things down and don't want to deal with vscode.

Copying and pasting text that is in a list creates an unexpected newline at paste.

To reproduce,
type - word
copy word
paste inside of same line, and a new line will be inserted

[gr-hayduk]

Well, the copy/paste seems to be more complex problem than just producing newlines. You cannot safely delete them.
I have a "todo" list formatted with "- [ ] text1" lines and something strange gets inserted between the lines (splitting the list into non-joinable groups).
Sometimes the "[ ]"/"[x]" just disappear "automagically" and I end up having plain "- ..." formatted list.
Simply can't figure out what rules there are in auto-formatting of what I type or copy or paste.
If this has any chances to be fixed, I can try to find out rules what breaks the newlines or lists or todo-marks ([ ]).
I've figured out that copying some lines from MarkTwo and pasting into Notepad++ (simple text), has a UTF-8 character 0xE2 0x80 0x82 (Notepad++ shows ZWSP, but in saved file I see these three bytes). Maybe it'll help in debugging the issue.
Also, pasting more than one line from Notepad++ makes one line in MarkTwo??? So it's not possible to select all ToDo contents in MarkTwo copy somewhere else and paste again into MarkTwo?