try now let's see if we did some progress
i did a mistake after you flash the firmware replace that in l1profile.dat
Default
INDEX0=MT7915D
INDEX0_profile_path=/etc/wireless/mt7615/mt7615.1.dat;/etc/wireless/mt7615/mt7615.2.dat
INDEX0_EEPROM_offset=0x0
INDEX0_EEPROM_size=0x20000
INDEX0_EEPROM_name=e2p
INDEX0_main_ifname=ra0;rax0
INDEX0_ext_ifname=ra;rax
INDEX0_wds_ifname=wds;wdsx
INDEX0_apcli_ifname=apcli;apclix
INDEX0_single_sku_path=/etc_ro/Wireless/SingleSKU_mt7615e-sku.dat
INDEX0_bf_sku_path=/etc_ro/Wireless/SingleSKU_mt7615e-sku-bf.dat