don't assume what programme the file should be executed with, it may not be the same shell.

.xinitrc

@@ -1,10 +1,9 @@
 #!/usr/bin/env sh
-# shellcheck disable=SC1090,SC1091
 
 # load system xinit scripts
 if [ -d /etc/X11/xinit/xinitrc.d ]; then
 	for f in "/etc/X11/xinit/xinitrc.d"/?*.sh; do
-		. "$f"
+		./"$f"
 	done
 	unset f
 fi
@@ -22,8 +21,8 @@ export __GL_SYNC_TO_VBLANK=0         # disable vsync in driver, to aid with some
 numlockx on # ensure numlock is on before setting keymap
 
 setxkbmap us -variant altgr-intl -option ''         # load the correct keymap which actually has 3rd level shift
-[ -f "/etc/xprofile" ] && . "/etc/xprofile"     # load the system-wide xprofile
-[ -f "$HOME/.xprofile" ] && . "$HOME/.xprofile" # load the local xprofile configuration
+[ -x "/etc/xprofile" ] && "/etc/xprofile"           # load the system-wide xprofile
+[ -x "$HOME/.xprofile" ] && "$HOME/.xprofile"       # load the local xprofile configuration
 [ -f "$HOME/.Xmodmap" ] && xmodmap "$HOME/.Xmodmap" # load local keymap
 
 [ -x /usr/bin/picom ] && /usr/bin/picom -b # start picom as a background service