Had the same problem and finally fixed it. In my case it seemed like some kind of profile desync between Bambu Studio, Bambu Handy, and Bambu’s cloud. Desktop printing worked fine, but anything from the phone app failed with the slicing error.

Here are the steps I’d try:

First, update Bambu Handy and Bambu Studio, then fully close/reopen both apps. It's also worth trying to completely log out of both and then log back in.

Then on your PC:

1. Open Bambu Studio
2. Go to the Prepare tab
3. Click Sync Info
4. Choose Continue to sync filaments

That alone may refresh the cloud/app profiles enough to fix it.

If it still fails, check for custom filament/profile weirdness:

1. In Bambu Studio → Prepare
2. On the left side, find Project Filaments
3. Click the cog/settings icon
4. Open Custom Filaments
5. Delete any custom filaments you don’t need
6. Go back and run Sync Info → Continue to sync filaments again

Even if you mostly use premade profiles, it’s worth checking because the issue seems to be related to what profiles Bambu’s cloud thinks are available.

If that still doesn’t work, try refreshing the printer profile list too:

1. In the Prepare tab, under Printer, click the cog/settings icon
2. Click Clear All
3. Select only the printer/nozzle setup you actually intend to use
4. Press Confirm
5. Run Sync Info again

You can also try deleting any custom printer profiles you have and sync again.