Downloaded files occasionally fail to save on SPIKE Prime Hub after reboot

[robos-education]

I have a question regarding the SPIKE Hub.

Occasionally, files downloaded to the SPIKE Hub are not saved after a reboot.

Here are a few details I've already confirmed:

I've ruled out issues with the slots or the battery.

It isn't a code size issue either—the total code across all modules is well within 1,500 lines.

I always power off the Hub using the center button, so it isn't an improper shutdown issue.

Since this happens only intermittently, it's hard to pin down. Could this issue occur if the Hub is powered off while still connected to a PC via BLE?

Has anyone experienced something similar, or does anyone know what might be causing this?

pybricks v3.0.1
('primehub', '4.0.1', 'ci-release-101-v4.0.1 on 2026-06-24')

[laurensvalk]

Thank you! I am currently looking for a way to reproduce it.

I would be grateful for your help. If you are able to reproduce it somewhat reliably, you will be able to confirm the fix later.

Here is a "big" program that just turns the light on. Then you can turn the hub off and on, and still see the color when you start it.

big.py

You could change the color to something else if it doesn't reproduce the first time, and so on.

Bluetooth could indeed be related, so it would probably best to test it with Bluetooth, like you were doing already.

[robos-education]

Thanks for the response.
Since the exact cause is unclear, I’ll assume a different slot was running for now.
I’ll bring this up again if the issue appears under more specific conditions.

[laurensvalk]

Thank you. So potentially there is no saving issue. This is great to hear.

We'll definitely look at making the slots easier to see and use. Thanks!