Lightroom keyword problem

I use Lightroom 5.7.1, with a keyword list set up using hierarchies. Normally when I assign a keyword to a picture all the keywords higher in the hierarchy are picked up also - for example, "sparrow" would pick up "songbird" and "bird."
I've installed the same Lightroom on a second computer that I'm planning to migrate to, but when I assign a keyword it's not picking up all the others in the hierarchy - "sparrow" might or might not pick up "songbird" and definitely won't pick up "bird."
Anyone have this problem, or have any ideas?

Keywords have a couple of different settings that can be applied. Two of them apply to hierarchies. "Include on export" - if this is ticked the keyword will be included. "Export containing keywords" - this means include all the keywords above this one in the hierarchy.

If one of the keywords higher up the hierarchy has "include on export" unticked that will override any lower keyword that has "Export containing keywords" and that higher keyword wont be exported.

Those settings are applied, and are identical on both computers.

Can you be specific as to what you mean by "not picking up".

Could you upload a couple of screen shots of LR, one showing where the key word hierarchy is working, and one where it isn't. Then we can try and spot the difference.

Thank you all for the replies on this, but I found my problem!

In the "Keyword Tags" box "Enter Keyword" was selected instead of "Will Export".

I was pretty sure I was overlooking something right in front of me that I had set wrong, I just had trouble seeing it.

Thanks again