FYI – That character in the menu is, and has always been a number 3 – that doesn’t change. It is the font used for the 3 that is the issue. The dropdown ‘caret’ symbol is a numerical 3. The glyph/shape in the ETModules font that represents the ascii character 51 decimal 33 Hexidecimal (the number 3) is the caret symbol (the v like shape). If your css gets disconnected in some way – the munu doesnt know to use the symbol font and renders it with a fallback (non symbol) standard font – hence the 3 appears again.
So you look to find out why the font css has broken.