You likely flashed the wrong board revision. Check your Wi-Fi chip physically. If it says SV6256 but you flashed HS2734A , Wi-Fi will fail. Re-flash the correct exclusive version.
Most T95H units are sold by unbranded Chinese ODM factories (e.g., Sunvell, TANIX, VONTAR). They host firmware on: t95h android tv box firmware download exclusive
Installing firmware meant for a different processor (like an Amlogic chip) will permanently brick your device. This guide is strictly for the Allwinner H616 T95H variant. You likely flashed the wrong board revision