Tether internet access from my mobile phone is lost

[atux_null]

I would like to use my mobile phone to tether through usb in OpenWRT.
i have followed this guide in wiki https://openwrt.org/docs/guide-user/network/wan/smartphone.usb.tethering and i installed the packages:

opkg install kmod-usb-net-rndis kmod-usb-net-cdc-eem kmod-usb-net-cdc-ether kmod-usb-net-cdc-subset  kmod-nls-base kmod-usb-core kmod-usb-net kmod-usb-net-cdc-ether kmod-usb2 

after installing all the aforementioned packets, then i did a reboot. I created a new interface, i assigned the usb0 and then i was able to access the internet.
some time later i noticed that i do not have access to the internet. By checking the interfaces i see that the tethering says that interface is not present. Abandoned usb0 device
i did a couple of reboots, without success.
any ideas please?

[brada4]

Phone discharged and switched off?

[AndrewZ]

Reconnect the phone, observe messages on its screen, allow tethering if required.
Then show the output of cat /sys/kernel/debug/usb/devices

[mk24]

Also run ip link show dev usb0 to confirm that it is UP and LOWER_UP. If not it is likely that the phone side has stopped serving the link.

[atux_null]

for some strange reason i had to re-install everything!!! No idea why.
Now it works.