Routing between 2 points on the same path not working

Yes it looks like access=forestry on the track may be the problem, used on its own it implies all forms of non-forestry access are not allowed (including foot, bicycle, horse). Depending on what is in fact allowed, it might be fixed by making this tag narrower e.g. motor_vehicle=forestry, as suggested at https://wiki.openstreetmap.org/wiki/Tag:access=forestry?uselang=en-GB . You could also add specific modes to override the main access tag, e.g. foot=yes. Ideally based on what is signed on the ground.

(I couldn't get the original link to work either by the way).

Thanks Alan & Andy. With foot=allowed routing works as expected.

Please note that the correct tag is foot=yes and not foot=allowed.

Checking again. Clicking on foot=allowed does in fact insert foot=yes when viewed in advanced mode so I think we are all ok :-)

Not directly related to the original question, but:

I suspect the footpath tag should have foot=allowed or in England foot=designated to indicate it is a legal footpath

is actually a bit confusing, and not just because "allowed" should be "yes" of course.

The "foot" tag on something describes how it is legal to access it by that mode of transport. Somewhat confusingly, "foot=designated" is also used with "highway=path" to indicate that the thing being discussed is actually designed as a footway not any other sort of path.

What I suspect Andy is alluding to here is the "designation=public_footpath" tag, which is used in England and Wales to indicate a special legal status, which also implies foot=yes (but I'd always add a foot=yes tag too, to avoid problems like this one).