[WP7605][SW] Could not attach 3G NW after executing custom application

Back Ground:
After executing custom application as attached, WP7605 have never been attached 3G NW(Callbox).

If I use the shipment WP7605 as SKU#1104608, it can be attached 3G NW, but after executing custom application, it is failed.

I think there is any influence to be detached 3G NW by executing our application.

Question:
Please see the attached command list, and is there any process to be detached 3G NW?
(Of course, Modem, yocto, and legato framework is same between OK case and NG case.)

Best Regards,

EXITTEST.txt (3.1 KB)

seems the only related line are as follows:
echo “AT!IMPREF=“SOFTBANK”” > /dev/ttyAT

Can you comment out this line and confirm?

Hi, jyijyi

Make sense, thanks!
Let me check it, so if I have an additional trouble, I will ask it in other PF.
Thank you for your support quickly.