[Bug] Import of a zip file fails on beta V3

[BertLindeman]

Describe the bug
Import of a zip file fails with v4.0.0b9 (Pybricks Beta v3.0.0-beta.6) on Brave browser
Details below.
Import succeeds with v4.0.0b8 (Pybricks Beta v2.3.0-beta.1) on Chrome

To reproduce
Steps to reproduce the behavior:

1. Go to beta.pybricks.com
2. Click on update
3. Click on import a file
4. Select a zip file (On v2.3 first change the filetype to zip)
5. Click 'open'
6. See error

Expected behavior
What did you expect to happen instead?
Would be nice if v3 also import a zipfile correctly like v2..3

Screenshots
There is a saying that a picture is worth a 1000 words. Screenshots really help to identify and solve problems.

Related
File selection update on v3 fixed #2114

Details
Works on Chrome with

MicroPython for LEGO® Powered Up smart hubs.
v4.0.0b8 (Pybricks Beta v2.3.0-beta.1)
Copyright (c) 2020-2026 The Pybricks Authors

With browser Brave
Brave 1.89.137 (Official Build) (64-bit)
Chromium: 147.0.7727.102
And

MicroPython for LEGO® Powered Up smart hubs.
v4.0.0b9 (Pybricks Beta v3.0.0-beta.6)
Copyright (c) 2020-2026 The Pybricks Authors

unzip -9 file:

Error: 'm258673.zip' has unsupported file type: application/x-zip-compressed
    at _b (https://beta.pybricks.com/static/js/main.fc2fb50b.js:2:502429)
    at _b.next (<anonymous>)
    at h (https://beta.pybricks.com/static/js/main.fc2fb50b.js:2:1391578)
    at l (https://beta.pybricks.com/static/js/main.fc2fb50b.js:2:1391895)

windows copy to zipped path:

Error: 'm258673.zip' has unsupported file type: application/x-zip-compressed
    at _b (https://beta.pybricks.com/static/js/main.fc2fb50b.js:2:502429)
    at _b.next (<anonymous>)
    at h (https://beta.pybricks.com/static/js/main.fc2fb50b.js:2:1391578)
    at l (https://beta.pybricks.com/static/js/main.fc2fb50b.js:2:1391895)

from pybricks downloads zip:

Error: 'pybricks-backup-BRAVE-2026-04-21_10-35-38.zip' has unsupported file type: application/x-zip-compressed
    at _b (https://beta.pybricks.com/static/js/main.fc2fb50b.js:2:502429)
    at _b.next (<anonymous>)
    at h (https://beta.pybricks.com/static/js/main.fc2fb50b.js:2:1391578)
    at l (https://beta.pybricks.com/static/js/main.fc2fb50b.js:2:1391895)