Xterm does not display one uni-code character

The character is actually not in the font you indicated. You can see this using xfd:

xfd -fa inconsolata

That shows the last codepoint is U+2423. Reading a little further, it turns out that the character is in the Unicode private use area, and (notwithstanding the fact that some font may provide it) has no standard meaning.

Since late 2018, xterm can load multiple TrueType fonts, but none of the fonts at hand have U+E0A0.

If you can identify the actual font which is used, someone can point out which versions of xterm can deal with it.

Addressing a comment about terminator (which I don't happen to have installed), terminator doesn't use the same library interfaces as xterm, which affect the font-searching (none of either is well documented). You could use strace to see which font-files it actually opens.

For example, exploring this a little with strace, konsole and pterm on my Debian/testing both open one of the OpenOffice fonts for this character:

2600  openat(AT_FDCWD, "/users/tom/foo", O_RDONLY               
2600  )             = 3                                     
2586  openat(AT_FDCWD, "/usr/share/fonts/truetype/openoffice/opens___.ttf", O_R>
2601  openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC   
2601  )             = 4                 

(That's the "OpenSymbol" family's file).

On the other hand, I see that rxvt-unicode does not display the character, in spite of having several font-patterns added to its search-list to (try to) work around problems such as this (which ultimately reflects a problem in fontconfig). Very likely you'd find something similar (but different) in the libraries which support konsole and pterm.