Lots of things need improvement.
I read somewhere the win-spout plugin was causing issues with AMD GPU's. I'm not sure if it's been fixed as I don't use either but you may want to look into it some more.
Audio lag may indicate system overload or may be due to the bad audio routing currently in play. Better not to mix Global & Source audio. Also, that Rendering lag is in fact GPU overload so load reduction is in order.
13:14:24.291: Max audio buffering reached!
13:14:24.291: adding 725 milliseconds of audio buffering, total audio buffering is now 960 milliseconds (source: SFX)
13:14:24.291:
13:14:24.291: Source SFX audio is lagging (over by 1404381.82 ms) at max audio buffering. Restarting source audio.
13:23:08.548: Source SFX audio is lagging (over by 515857.05 ms) at max audio buffering. Restarting source audio.
13:25:03.065: Source SFX audio is lagging (over by 97352.10 ms) at max audio buffering. Restarting source audio.
13:26:19.461: [win-wasapi: 'SFX'] update settings:
13:26:19.461: device id: {0.0.0.00000000}.{d194fc6d-ee3d-48b0-b35c-c037a476d50f}
13:26:19.461: use device timing: 1
13:35:25.814: User switched to scene 'Ending'
13:35:30.316: [game-capture: 'Fishing'] capture stopped
13:35:30.317: [win_spout] [PNG Mini] Getting info for sender veadotube mini
13:35:30.317: [win_spout] [PNG Mini] Sender veadotube mini is of dimensions 830 x 895
13:35:56.341: [rtmp stream: 'adv_stream'] User stopped the stream
13:35:56.342: [rtmp stream: 'adv_stream'] Socket send buffer is 2097152 bytes
13:35:56.343: Output 'adv_stream': stopping
13:35:56.343: Output 'adv_stream': Total frames output: 651092
13:35:56.343: Output 'adv_stream': Total drawn frames: 633892 (651220 attempted)
13:35:56.343: Output 'adv_stream': Number of lagged frames due to rendering lag/stalls: 17328 (2.7%)
13:35:56.343: [rtmp stream: 'adv_stream'] Freeing 1 remaining packets
13:35:56.345: Video stopped, number of skipped frames due to encoding lag: 17358/651151 (2.7%)
13:35:56.352: ==== Streaming Stop ================================================
13:35:57.435: Output 'Vertical Backtrack': stopping
13:35:57.435: Output 'Vertical Backtrack': Total frames output: 651149
13:35:57.435: Output 'Vertical Backtrack': Total drawn frames: 633883 (651212 attempted)
13:35:57.435: Output 'Vertical Backtrack': Number of lagged frames due to rendering lag/stalls: 17329 (2.7%)
13:35:57.435: Video stopped, number of skipped frames due to encoding lag: 17632/651210 (2.7%)
Disable this: Game DVR: On
Fix these, 8-bit is the correct setting, it doesn't appear that HDR is enabled on your system so check here
Set refresh rates to 60, your 3rd monitor is set-up OK.
09:22:09.742: output 0:
09:22:09.742: name=LG ULTRAGEAR
09:22:09.742: pos={0, 0}
09:22:09.742: size={1920, 1080}
09:22:09.742: attached=true
09:22:09.742: refresh=144 > 60
09:22:09.742: bits_per_color=10 > 8
09:22:09.742: space=RGB_FULL_G22_NONE_P709
09:22:09.742: primaries=[r=(0.675781, 0.320312), g=(0.297852, 0.639648), b=(0.146484, 0.060547), wp=(0.312500, 0.329102)]
09:22:09.742: relative_gamut_area=[709=1.192310, P3=0.878936, 2020=0.630578]
09:22:09.742: sdr_white_nits=80
09:22:09.742: nit_range=[min=0.249700, max=351.000000, max_full_frame=351.000000]
09:22:09.742: dpi=96 (100%)
09:22:09.742: id=\\?\DISPLAY#GSM5BB8#7&2ec0ba4e&0&UID260#{e6f07b5f-ee97-4a90-b076-33f57bf4eaa7}
09:22:09.742: alt_id=\\.\DISPLAY3
09:22:09.744: output 1:
09:22:09.744: name=LG ULTRAGEAR
09:22:09.744: pos={1920, 0}
09:22:09.744: size={1920, 1080}
09:22:09.744: attached=true
09:22:09.744: refresh=180 > 60
09:22:09.744: bits_per_color=10 > 8
09:22:09.744: space=RGB_FULL_G22_NONE_P709
09:22:09.744: primaries=[r=(0.647461, 0.337891), g=(0.315430, 0.625000), b=(0.152344, 0.059570), wp=(0.313477, 0.329102)]
09:22:09.744: relative_gamut_area=[709=1.046693, P3=0.771592, 2020=0.553565]
09:22:09.744: sdr_white_nits=80
09:22:09.744: nit_range=[min=0.297000, max=301.000000, max_full_frame=301.000000]
09:22:09.744: dpi=96 (100%)
09:22:09.744: id=\\?\DISPLAY#GSM5C93#7&2ec0ba4e&0&UID256#{e6f07b5f-ee97-4a90-b076-33f57bf4eaa7}
09:22:09.744: alt_id=\\.\DISPLAY1
Some Scenes are bugged with Multiple Display, Game or Window Captures. Only (1) per Scene to avoid interference.
Fix that stuff, run another test & post the log. I suspect this may not be enough to eliminate all the lag but it's a start. As you can see both Audio & Video are lagging......
13:36:17.929: audio_thread(Audio): min=0.017 ms, median=4.737 ms, max=1259.58 ms,
99th percentile=22.602 ms
13:36:17.929: obs_graphics_thread(16.6667 ms): min=0.092 ms, median=2.271 ms, max=1256.52 ms,
99th percentile=24.63 ms, 98.1729% below 16.667 ms
13:36:17.929: ┣tick_sources: min=0.001 ms, median=0.236 ms, max=639.371 ms, 99th percentile=4.012 ms
13:36:17.929: ┣output_frame: min=0.075 ms, median=1.78 ms, max=1253.49 ms,
99th percentile=19.135 ms