EA6350 V3 Revert to Original firmware

Dear members
i hope someone can help me

i have a linksys EA6350 V3 router ,i flashed a custom firmware provided by some members , because the project for EA6350 v3 is young i got poor wifi performance , when i tried to revert back to the original firmware from luci interface, it didn't work , the router always boot to openwrt with Luci , i tried with ssh

wget "firmware" and sysupgrade -f the same issue

i really need to get it back please help me

thanks in advance