Subtitles not downloading from polish website 35mm.online

[WimieZasad]

I have been able to succesfuly download free to watch DRM protected videos using the WidevineProxy2 extension on firefox, and running the following command in N_m3u8DL-RE :

PS C:\Downloads\N_m3u8DL-RE_v0.5.1-beta_win-x64_20251029> .\N_m3u8DL-RE.exe "https://n-25-14.dcs.redcdn.pl/dash/o2/wfdif/cps/prod/vod/5607c977-7221-4aa3-b5e6-d4a2df5c43ed/MOVIE/LIBCODER_SMOOTH_1080_WFDIF/Manifest.ism?indexMode" -H "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:150.0) Gecko/20100101 Firefox/150.0" -H "Accept: */*" -H "Origin: null" -H "Referer: https://35mm.online/" -H "Sec-GPC: 1" --key f0935dfed1fd1948982c854892dd9026:4dd70aaa3d6d1bd1c c8881acb5577e8e --decryption-engine MP4DECRYPT -M format=mkv --save-dir "C:\Users\output"

However I have not been able to download the english subtitles which you can toggle in the actual 35mm.online website that's playing videos. N_m3u8DL-RE does not detect them:

00:04:37.513 INFO : Extracted, there are 7 streams, with 6 basic streams, 1 audio streams, 0 subtitle streams

And when i try using all subtitle related commands:

PS C:\Downloads\N_m3u8DL-RE_v0.5.1-beta_win-x64_20251029> .\N_m3u8DL-RE.exe "https://n-25-14.dcs.redcdn.pl/dash/o2/wfdif/cps/prod/vod/5607c977-7221-4aa3-b5e6-d4a2df5c43ed/MOVIE/LIBCODER_SMOOTH_1080_WFDIF/Manifest.ism?indexMode" -H "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:150.0) Gecko/20100101 Firefox/150.0" -H "Accept: */*" -H "Origin: null" -H "Referer: https://35mm.online/" -H "Sec-GPC: 1" --key f0935dfed1fd1948982c854892dd9026:4dd70aaa3d6d1bd1c c8881acb5577e8e --decryption-engine MP4DECRYPT -M format=mkv --save-dir "C:\Users\output" --select-subtitle all --sub-format SRT --auto-subtitle-fix
00:04:19.342 INFO : N_m3u8DL-RE (Beta version) 20251029
00:04:19.365 INFO : Loading URL: https://n-25-14.dcs.redcdn.pl/dash/o2/wfdif/cps/prod/vod/5607c977-7221-4aa3-b5e6-d4a2d....ism?indexMode
00:04:19.527 INFO : Content Matched: Dynamic Adaptive Streaming over HTTP
00:04:19.530 INFO : Parsing streams...
00:04:19.658 WARN : Writing meta json
00:04:19.677 INFO : Extracted, there are 7 streams, with 6 basic streams, 1 audio streams, 0 subtitle streams
00:04:19.679 INFO : Vid *CENC 1920x1080 | 3950 Kbps | 2 | avc1.640028 | 500 Segments | Main | ~16m38s
00:04:19.680 INFO : Vid *CENC 1280x720 | 2550 Kbps | 3 | avc1.64001f | 500 Segments | Main | ~16m38s
00:04:19.681 INFO : Vid *CENC 1024x576 | 1550 Kbps | 5 | avc1.64001f | 500 Segments | Main | ~16m38s
00:04:19.682 INFO : Vid *CENC 960x540 | 950 Kbps | 6 | avc1.64001f | 500 Segments | Main | ~16m38s
00:04:19.682 INFO : Vid *CENC 640x360 | 550 Kbps | 1 | avc1.4d401e | 500 Segments | Main | ~16m38s
00:04:19.683 INFO : Vid *CENC 416x234 | 300 Kbps | 4 | avc1.4d400d | 500 Segments | Main | ~16m38s
00:04:19.684 INFO : Aud *CENC 7 | 128 Kbps | mp4a.40.2 | pol | 2CH | 500 Segments | Main | ~16m38s
Unhandled exception: System.Exception: No stream found to download
at N_m3u8DL_RE.Program.<DoWorkAsync>d__3.MoveNext() + 0x2295
--- End of stack trace from previous location ---
at System.CommandLine.Command.<>c__DisplayClass33_0.< <SetAction>b__0>d.MoveNext() + 0x51
--- End of stack trace from previous location ---
at System.CommandLine.Invocation.InvocationPipeline.< InvokeAsync>d__0.MoveNext() + 0x1d2

The subtitles are not embedded in the mkv output file either, so im having trouble figuring out the solution. When looking at the network tab of the video stream i could not find any subtitle files too. The playlist files are .ism , if that helps. Can someone please help me out here?

[xangetsue]

in the network tab search box type vtt then refresh the page and play the video and activate the subtitle