OpenWrt 21.02.0-rc1 on AGPWI (ADB P.DG A4001N A-000-1A1-AX)

Hi support,
I trying this version on my AGPWI (official firmware) but not work fine, crashes all the time, I can't understand how an official firmware works bad on this router. I can to install only support 3G/4G, if i try to install any other package the router block, i must to reboot.
What could be the problem ?
how can I solve this problem ?

Configuration of my AGPWI ( 16 flash / 32 ram), I don't believe that is lack of memory.

regards,
Alfonso

Is there a question somewhere ?

If I use the router only via wifi, without connecting a device via LAN, it crashes all the time.
While if I use the same via wifi and with a device connected via LAN, everything works perfectly ?

regards,
Alfonso