Keycode at beginning of a line is not recognized

[gpanders]

Actual behavior

Example (from windows.txt, line 131):

CTRL-W s						*CTRL-W_s*
CTRL-W S						*CTRL-W_S*
CTRL-W CTRL-S						*CTRL-W_CTRL-S*

The only (keycode) element here is CTRL-S. All of the CTRL-W words are captured as (word) instead of (keycode).

Expected behavior

All of the CTRL-W words should be captured as keycodes.

Below is the syntax tree as viewed in the inspector in Nvim:

(block) ; [131:1 - 138:0]
 (line) ; [131:1 - 132:0]
  (word) ; [131:1 - 6]
  (word) ; [131:8 - 8]
  (tag) ; [131:15 - 24]
   "*" ; [131:15 - 15]
   text: (word) ; [131:16 - 23]
   "*" ; [131:24 - 24]
  "\n" ; [131:25 - 132:0]
 (line) ; [132:1 - 133:0]
  (word) ; [132:1 - 6]
  (word) ; [132:8 - 8]
  (tag) ; [132:15 - 24]
   "*" ; [132:15 - 15]
   text: (word) ; [132:16 - 23]
   "*" ; [132:24 - 24]
  "\n" ; [132:25 - 133:0]
 (line) ; [133:1 - 134:0]
  (word) ; [133:1 - 6]
  (keycode) ; [133:8 - 13]
  (tag) ; [133:20 - 34]
   "*" ; [133:20 - 20]
   text: (word) ; [133:21 - 33]
   "*" ; [133:34 - 34]
  "\n" ; [133:35 - 134:0]