Can anyone explain why on the 14 Oct 2022 at 7.00 UTC at location (Lat 52.339 Long 0.419)does the waning gibbous moon (Alt 39º) appear to be illuminated from a different direction, i.e. slightly upwards, than from the sun which is only at Alt 5º? The azimuth difference is 149.83º.
The lit part of the moon points directly towards the sun along a great circle.
Great circles are "straight lines" on a sphere.
You may be aware that the most direct line between two points on a sphere is not (usually) parallel to the equator, but is a great circle. This means the when flying (for example) from London to Tokyo, the direct route takes a plane over Northern Siberia, and the initial direction of the flight is North-east (even though Tokyo is well to the south of London)
The same effect is occurring here, but on the sphere of the sky. The direct line from the moon to the sun points up in the sky and this is the side of the moon that is lit by the sun. It is an optical illusion that the direct line should have constantly decreasing altitude.
Since both the sun and moon are on (or near) the ecliptic, which is a great circle in the sky, the lit part of the moon should point in the direction of the ecliptic. The two images below confirm this.
This image shows the moon and the sun on the ecliptic. While it appears curved in this projection, it is in fact a straight line in the sky.
This shows the lit part of the moon points in the direction of the ecliptic, and so straight towards the sun.
Images from Stellarium
There are no actual celestial spheres or curved ecliptic lines - they are just there for the convenience of plotting and predicting positions. The movement of the moon has nothing to do with the way it is illuminated. Only its position in the sky with respect to the sun affects this. You may observe the moon moving in a great circle but the light from the sun doesn't move in a circle - it travels in a straight line towards the moon. If you place a ball on top of a poll coincident with the moon and a bright light on top of a pole coincident with the sun then observation will show a straight line between the light and the ball. Its the same when the sun shines on any object, trees, houses, balls etc and the moon is no different. Is just a matter of scale. The image should be self explanatory.