No idea how that's being handled or if it actually disabled the settings. I've streamed before using HLS with no issues but it's been a few years. Anyway, on my set-up all that Network stuff is always set at default. No Dynamic bit-rate or optimizations in play. According to the non HDR log, you have both enabled.
I looked at the HDR log, there was no dropped frames when you were streaming @ 15,000kbps, frames started dropping when you went above that bit-rate. The higher you go, the worse it gets....
13:10:21.347: [obs-nvenc: 'advanced_video_stream'] settings:
13:10:21.347: codec: HEVC
13:10:21.347: rate_control: CBR
13:10:21.347: bitrate: 15000
13:10:21.347: cqp: 20
13:10:21.347: keyint: 60
13:10:21.347: preset: p5
13:10:21.347: tuning: hq
13:10:21.347: multipass: disabled
13:10:21.347: profile: main10
13:10:21.347: width: 3840
13:10:21.347: height: 2160
13:10:21.347: b-frames: 4
13:10:21.347: lookahead: true
13:10:21.347: psycho_aq: true
13:10:21.347:
13:10:21.451: ---------------------------------
13:10:21.451: [FFmpeg aac encoder: 'adv_stream_audio'] bitrate: 160, channels: 2, channel_layout: stereo
13:10:21.451:
13:10:21.452: [ffmpeg muxer: 'adv_stream'] Using muxer settings:
13:10:21.452: method=PUT
13:10:21.452: http_persistent=1
13:10:21.452: ignore_io_errors=1
13:10:21.452: http_user_agent=libobs/30.2.3
13:10:21.452: hls_time=2
13:10:21.459: YT: GetYTApi() Failed to get Auth
13:10:21.459: ==== Streaming Start ===============================================
13:10:21.459: [ffmpeg hls muxer: 'adv_stream'] Writing to path '
https://a.upload.youtube.com/http_upload_hls?cid={stream_key}©=0&file=out.m3u8'...
13:10:50.254: User switched to scene 'DKH'
13:10:51.356: User switched Program to scene 'DKH'
13:10:51.371: User switched to scene 'Black'
13:10:55.759: User switched to scene 'DKH'
13:13:18.170: [ffmpeg muxer: 'adv_stream'] Output of file '
https://a.upload.youtube.com/http_upload_hls?cid={stream_key}©=0&file=out.m3u8' stopped
13:13:18.170: Output 'adv_stream': stopping
13:13:18.170: Output 'adv_stream': Total frames output: 5237
13:13:18.170: Output 'adv_stream': Total drawn frames: 5302
13:13:18.171: YT: GetYTApi() Failed to get Auth
13:13:18.171: ==== Streaming Stop ================================================
14:23:06.803: codec: HEVC
14:23:06.803: rate_control: CBR
14:23:06.803: bitrate: 21000
14:24:21.434: Output 'adv_stream': Number of dropped frames due to insufficient bandwidth/connection stalls: 528 (24.4%)
13:09:05.434: codec: HEVC
13:09:05.434: rate_control: CBR
13:09:05.434: bitrate: 25000
13:10:07.857: Output 'adv_stream': Number of dropped frames due to insufficient bandwidth/connection stalls: 704 (38.9%)
14:24:35.204: codec: HEVC
14:24:35.204: rate_control: CBR
14:24:35.204: bitrate: 41000
14:37:27.879: Output 'adv_stream': Number of dropped frames due to insufficient bandwidth/connection stalls: 15395 (66.6%)