I just confirmed that sorting does not work in the latest commit 1f22f54. I am now going to test the fix.

From what I can tell the issue persists. I likely need more context. I believed the goal was to fix the reverse button. I would guess that it would yield a different ticket order but it did not for me.

I cloned your repo and built a docker image with

'''
docker build --progress=plain -t djangohelpdesk/standalone:latest -f standalone/Dockerfile .
cd standalone
docker compose up
'''

I was worried somehow I had an old image so I ran docker exec -it standalone-django-helpdesk-1 bash and verified the python files contained your changes.

Am I testing the wrong thing?

It's working for me. To verify, I did a clean install from the latest revision in my helpdesk repo. I have some custom styles in my dev env which is why the filters are tabbed, but that shouldn't be impacting their functionality at all.

When /tickets/ is first loaded:

When sorting="title" and the form is submitted:

And when sorting="title" and reverse is checked, then the form submitted:

I still cant replicate the success. Can you tell me what database you're using and the python/django versions?

The standalone uses postgresql 17 and

python --version
Python 3.11.12

pip list 
...
Django                 5.2
django-appconf         1.1.0
django-bootstrap4-form 4.0.2
django-cleanup         9.0.0
django-helpdesk        1.4.0       /opt/django-helpdesk
django-model-utils     5.0.0
django-reversion       5.1.0
django-user-accounts   3.3.2
djangorestframework    3.16.0
...

Also I'm going to bring in the big guns as they might have a better idea of whats happening.
@uhurusurfa, @timthelion, @Benbb96