Date comparison for tasks not working as I expect. What am I missing?

[quantumgardener]

I've running with the new 0.4.11 version and can't get date comparison on tasks to work as I expect. So rather than post a bug, I'm asking here for help.

I have a page with:

- [ ] test task [due:: 2021-09-20]

In my understanding, this should set a due date of 20 September, 2021. So why does this query return nothing at all?

task where due = date("2021-09-20") and completed=false

I have tried various forms of testing and can't work out what I'm missing.

task where date(due) = date("2021-09-20") and completed=false

task where date(due).toString = date("2021-09-20").toString and completed=false

If I list:

table due from #test the date returned is 20 September, 2021 (Using #test just to filter the one page)

And if I try table date(due) as x, date("2021-09-20") as y from #test I will see in text the same date for each, but table (date(due) = date("2021-09-20")) as y from #test shows false. I understand this last statement may not even be a valid thing to ask.