I'd assume this is using ConEmu's ChildGui which means it hacks up a MinTTY window to appear inside ConEmu's GUI. MinTTY doesn't use a real terminal but rather pipes as the processes stdio. Any native (non-MSYS2) Windows program would have a problem with this.

The known workaround is to launch such programs using WinPTY (Available in the MSYS2 pacman), which creates a real console for the program in the background and communicates it's input/output so that it appear in the original console.

Sadly that is a limitation of Windows, as Windows does not supply a proper PTY interface and MSYS2/MinTTY choose not to use something like WinPTY by default.