MobaXTerm Powerline Font Issue
Because this is the only result on Google for this particular problem, I thought I'd add my solution.
You need to install a patched font in windows. You can find versions of the popular coding fonts here, as well as others using a Google search. These fonts add the Powerline symbols in the Unicode Private Use area, but otherwise, the fonts are the same.
Restart MobaXTerm so the newly installed fonts appear. Under Settings > Terminal change the font to whichever patched font you installed.
MobaXTerm saves the font setting independently in any saved sessions, so you will need to edit each one of those as well. Right-click > Edit Session > Terminal Settings > Font.
Once again, MobaXTerm needs to be restarted for your changes to appear.
I had the same issue and reached out to support and they directed me to use this font, which appears to work . . .
https://github.com/halocaridina/.dotfiles_thinkpad_x230/blob/master/Xresources/.local/share/fonts/PragmataPro/PragmataPro%20for%20Powerline.ttf)