Flet freezes when doing expensive task in a thread

Duplicate Check

[X] I have searched the opened issues and there are no duplicates

Describe the bug

So, as it stands. If i do something computationally expensive in a thread, it locks the main thread and thus the app freezes.

Code sample

https://github.com/coreproject-moe/CoreProject/tree/1a5eb12b15327bcc31e160d2985f07766b54538d/seeder

Problematic code


    def did_mount(self):
        self.page.run_task(self.fetch_all_people)

    async def fetch_all_people(self):
        builder = StaffBuilder()
        dictionary = builder.build_dictionary(sort=True)

        async with self.session() as _session:
            for i in dictionary:
                db_obs = Staff(mal_id=i)
                _session.add(db_obs)
            await _session.commit()

Source

To reproduce

Copy the repository
poetry install
poetry run poe dev

Expected behavior

The Application should not freeze up

Screenshots / Videos

https://github.com/user-attachments/assets/1e3bf345-736d-440d-bd91-ab0bad8f43f1

Operating System

macOS

Operating system details

Windows 11

Flet version

0.23.2

Regression

No, it isn't

Suggestions

i think this could be because of either

GC call
Thread deadlock

Logs

None

Additional details