I have read the answers to a bunch of related questions, and it looks like the answer is to just not use sub-tasks if you want to use boards. I would understand if none of the sub-tasks we have defined appeared in the backlog, but some appear and some do not. I can find no rhyme or reason to why some do and some do not. I have removed the sub-filter from my board's settings, so that shouldn't be related.
Dear @Susan Williams,
I can imagine that all the questions are confusing. We should wipe there a little bit ;)
For Scrum Boards: In the backlog you will see only stories. And epics on the left side. Sub-tasks if stories are only shown as soon as a story is on the agile board (current sprint), by default.
In Kanban mode, where you do not have a backlog (planning is a ongoing permanently), the sub-tasks are visible from the beginning.
I should add that we have some stories, as far as I can tell their sub-tasks never appear in the backlog. But we also have tasks, which have sub-tasks that are "technical tasks", and sometimes those appear in the backlog along with their parents, but sometimes they do not. I can't see any obvious difference like they're in different states or anything. This is only on a kanban board, that's all I'm looking at.
We've been using Jira with just filters for quite awhile to track our development, but we have a larger number of products now sharing one project. I started using a kanban board so the swimlanes could help me track activity against each product.
I should say we have different groups of developers who have defined their own boards, I happen to only be using a kanban board. We haven't modified our issue types or workflow, and different tech leads are using whatever method works for them to try and keep track of their issues.
I see. This multiple boards on one project is often a source of troubles.
It's for me hard to get a clear picture of your current configuration. So any advice will just be a try.
I recommend to separate these multiple products within one project as good as possible, means an issue should not appear on two boards the same time.