There are two parts to a transcode, decoding the current format and encoding to the desired format (H.264 8-bit for Plex).
UHD 630 graphics cannot decode AV1 video. It can encode to H.264. When transcoding AV1 with UHD 630, you will not see a (hw) for the decode, but you will see a (hw) for the encode portion of the transcode.
Intel 11th Gen CPUs and later support decoding AV1 video (Wikipedia: Intel Quick Sync Graphics).
Nvidia Ampere and Ada Lovelace support AV1 decoding. See Nvidia Encode / Decode Matrix.
You do not mention which OS you are running.
When running Windows, Intel graphics are not supported for hardware accelerated tone mapping with public or beta releases of Plex Media Server. However, there is a Forum Preview release (pre-beta) that does support hardware accelerated tone mapping with Intel graphics. See [Plex Media Server] Forum Preview for Tonemapping on Windows with Intel iGPUs .
