Does not download multiple video-versions

[ghost]

Checklist

• I'm reporting a broken site support issue
• I've verified that I'm running youtube-dl version 2019.09.01
• I've checked that all provided URLs are alive and playable in a browser
• I've checked that all URLs and arguments with special characters are properly quoted or escaped
• I've searched the bugtracker for similar bug reports including closed ones
• I've read bugs section in FAQ

Verbose log

user@host:~$ youtube-dl -v -o '%(width)sx%(height)s_ytvideo.%(ext)s' -f '313+249/worstvideo[ext=webm]+worstaudio[ext=webm],bestvideo[ext=mp4]+bestaudio[ext=mp4]' https://www.youtube.com/watch?v=lfwjzNB--5k
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: [u'-v', u'-o', u'%(width)sx%(height)s_ytvideo.%(ext)s', u'-f', u'313+249/worstvideo[ext=webm]+worstaudio[ext=webm],bestvideo[ext=mp4]+bestaudio[ext=mp4]', u'https://www.youtube.com/watch?v=lfwjzNB--5k']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2019.09.01
[debug] Python version 2.7.13 (CPython) - Linux-4.9.0-9-amd64-x86_64-with-debian-9.9
[debug] exe versions: ffmpeg 3.2.14-1, ffprobe 3.2.14-1
[debug] Proxy map: {}
[youtube] lfwjzNB--5k: Downloading webpage
[youtube] lfwjzNB--5k: Downloading video info webpage
[download] 256x106_ytvideo.webm has already been downloaded and merged
user@host:~$ youtube-dl -v -o '%(width)sx%(height)s_ytvideo.%(ext)s' -f '313+249/worstvideo[ext=webm]+worstaudio[ext=webm],bestvideo[ext=mp4]+bestaudio[ext=mp4]' https://www.youtube.com/watch?v=lfwjzNB--5k
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: [u'-v', u'-o', u'%(width)sx%(height)s_ytvideo.%(ext)s', u'-f', u'313+249/worstvideo[ext=webm]+worstaudio[ext=webm],bestvideo[ext=mp4]+bestaudio[ext=mp4]', u'https://www.youtube.com/watch?v=lfwjzNB--5k']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2019.09.01
[debug] Python version 2.7.13 (CPython) - Linux-4.9.0-9-amd64-x86_64-with-debian-9.9
[debug] exe versions: ffmpeg 3.2.14-1, ffprobe 3.2.14-1
[debug] Proxy map: {}
[youtube] lfwjzNB--5k: Downloading webpage
[youtube] lfwjzNB--5k: Downloading video info webpage
[debug] Invoking downloader on u'https://r4---sn-5hnekn7z.googlevideo.com/videoplayback?expire=1567909856&ei=gBN0XbXcHoKMkwbaqqGICg&ip=185.220.101.26&id=o-AAXpJPyzk-0AXXcvCjmy2JmENnqIDaK25DbKn3PMwbDq&itag=278&aitags=133%2C134%2C135%2C136%2C137%2C160%2C242%2C243%2C244%2C247%2C248%2C278%2C298%2C299%2C302%2C303&source=youtube&requiressl=yes&mm=31%2C26&mn=sn-5hnekn7z%2Csn-4g5ednsy&ms=au%2Conr&mv=m&mvi=3&pl=24&initcwndbps=913750&mime=video%2Fwebm&gir=yes&clen=1332248&dur=150.650&lmt=1496925419935490&mt=1567888123&fvip=4&keepalive=yes&c=WEB&sparams=expire%2Cei%2Cip%2Cid%2Caitags%2Csource%2Crequiressl%2Cmime%2Cgir%2Cclen%2Cdur%2Clmt&sig=ALgxI2wwRgIhANL45ZY2a8IaEPUpRXmUpBB0vIUeOdNkgEZ3qj7HfsdJAiEAj10ejeCn8XxZeg5HXUAIgcjouXTTRRH4ITn8qoSUJxI%3D&lsparams=mm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps&lsig=AHylml4wRQIgGXFU7Kwexvt8gHuy6IMOK1Hl9VtjWTwXu_Am4nuq4FoCIQDsIl4yhz0YStPetVZuBkGVt5pY_aAZH_F42wccG4_aoQ%3D%3D&ratebypass=yes'
[download] Destination: 256x106_ytvideo.f278.webm
[download] 100% of 1.27MiB in 00:02
[debug] Invoking downloader on u'https://r4---sn-5hnekn7z.googlevideo.com/videoplayback?expire=1567909856&ei=gBN0XbXcHoKMkwbaqqGICg&ip=185.220.101.26&id=o-AAXpJPyzk-0AXXcvCjmy2JmENnqIDaK25DbKn3PMwbDq&itag=249&source=youtube&requiressl=yes&mm=31%2C26&mn=sn-5hnekn7z%2Csn-4g5ednsy&ms=au%2Conr&mv=m&mvi=3&pl=24&initcwndbps=913750&mime=audio%2Fwebm&gir=yes&clen=903197&dur=150.701&lmt=1496924989615852&mt=1567888123&fvip=4&keepalive=yes&c=WEB&sparams=expire%2Cei%2Cip%2Cid%2Citag%2Csource%2Crequiressl%2Cmime%2Cgir%2Cclen%2Cdur%2Clmt&sig=ALgxI2wwRgIhAO_BuJEBivXqSG8ipqSKrNq3Kzym5qLSx03glottoskZAiEAqhPv1YnQheHjqq2yFW8XFv_8MjIxhZZJZmb5Ne3y1dQ%3D&lsparams=mm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps&lsig=AHylml4wRQIgGXFU7Kwexvt8gHuy6IMOK1Hl9VtjWTwXu_Am4nuq4FoCIQDsIl4yhz0YStPetVZuBkGVt5pY_aAZH_F42wccG4_aoQ%3D%3D&ratebypass=yes'
[download] Destination: 256x106_ytvideo.f249.webm
[download] 100% of 882.03KiB in 00:01
[ffmpeg] Merging formats into "256x106_ytvideo.webm"
[debug] ffmpeg command line: ffmpeg -y -loglevel 'repeat+info' -i 'file:256x106_ytvideo.f278.webm' -i 'file:256x106_ytvideo.f249.webm' -c copy -map '0:v:0' -map '1:a:0' 'file:256x106_ytvideo.temp.webm'
Deleting original file 256x106_ytvideo.f278.webm (pass -k to keep)
Deleting original file 256x106_ytvideo.f249.webm (pass -k to keep)
user@host:~$ 

Description

In this command it should try to download the 4k Version, and if its not available (like in this case) it should download the worst AND best quality.

If there are arguments/conditions like [ext=webm] it does not work sometimes:

The example (the same like this from "verbose log") does not work and download only the first choosen quality (worstvideo with webm extension):
'313+249/worstvideo[ext=webm]+worstaudio[ext=webm],bestvideo[ext=mp4]+bestaudio[ext=mp4]'

But this for example works like expected(download worst AND best Video):
'313+249/worstvideo[ext=webm]+worstaudio[ext=webm],bestvideo+bestaudio'

And this also:
'313+249/worstvideo+worstaudio,bestvideo+bestaudio'

[dstftw]

bestaudio[ext=mp4] does not exist.