Installing v1 or v2 firmware on a v3 router will brick your device. Do not skip this step.
From archived forum discussions:
TP-Link India released a to resolve these exact issues. tplink tlwr850n v3 firmware download india fixed 2021
The issues leading up to the 2021 firmware release were a source of frustration for many users. Reports from various tech forums and Indian consumer complaint boards highlighted intermittent disconnections, difficulties in connecting specific ISP lines (such as those requiring VLAN tagging or specific PPPoE configurations common in India), and general system instability. For a non-technical user, these problems were baffling. The router would appear to work, only to drop the connection under load or fail to reconnect automatically after a power outage. These symptoms suggested that the existing firmware was not fully optimized for the specific network environments or the hardware nuances of the V3 board. Installing v1 or v2 firmware on a v3
He opened a command prompt and pinged Google. Time=14ms. TTL=117. Stable. He initiated a large file transfer from his cloud storage. The speed graph was a flat, high line—no spikes, no drops. The issues leading up to the 2021 firmware