mine logs it as such:

Info: Found H.264 encoder: h264_vaapi [vaapi]
Info: Found HEVC encoder: hevc_vaapi [vaapi]

after a bunch of messages about trying some codecs and setting bitrate and color depth for the found encoders. connecting with a client should show you no errors and a message with the selected encoder. you can try cpu encoding to see if that changes anything for a clue.

if the encoders are showing up as properly detected and selected in the logs, then you might want to look into something else as encoders are probably not the cause.