T8-G3 update offline?

[Offroad4ever]

Hey there,
I have three inverters from Foxess. I have a system that feeds entirely into the grid, i.e., without self-consumption. The purpose of this system is to produce as much electricity as possible. Currently, the system is offline because there is no grid. One of the inverters is always causing problems due to an AFCI error and keeps switching off. According to support, I need an update. However, it was not possible to get it online even with mobile internet.
Is there a way to update this local inverter?
It can't be that you can't simply operate such a simple system offline, can it?
Thank you very much for your help!

[Will]

Fox can email you the firmware bin file and there is a process to format a USB drive with the right folder structure for an offline update but honestly, it would be way easier to simply connect the inverter to temporary internet to update it over the cloud connection.