There can be different problems in relation to this. Probably some module overwrites the category page, so the ordering is not as expected.
If you installed some custom modules for the category page, I suggest to disable it, clean the cache and see if the sorting is okay after.
If you are unsure, you can also see the documentation page and if there are some extra options on this page (maybe some other module added that option).
Other than that, there are many other things that could cause this problem. For example, your theme overrides the sorting.
3
Answers
There can be different problems in relation to this. Probably some module overwrites the category page, so the ordering is not as expected.
If you installed some custom modules for the category page, I suggest to disable it, clean the cache and see if the sorting is okay after.
If you are unsure, you can also see the documentation page and if there are some extra options on this page (maybe some other module added that option).
Other than that, there are many other things that could cause this problem. For example, your theme overrides the sorting.
In my case, extension "Mageplaza_LayeredNavigation" was making this issue.
I disabled it and products start rendering with the assigned positions.
Thanks,
Mageplaza_LayeredNavigation was causing issues for my website too, so I have changed the text
relevance
toposition
in the below file path.and everything seems fine now, position sorting gets started working.