New issue by egorenar on void-packages repository

https://github.com/void-linux/void-packages/issues/25852

Description:
<!-- Don't request update of package. We have a script for that. https://alpha.de.repo.voidlinux.org/void-updates/void-updates.txt . However, a quality pull request may help. -->
### System

* xuname:  
  Void 5.8.16_1 x86_64 GenuineIntel notuptodate rrrrrmmdnFFFFFF
* package:  
  * webkit2gtk-2.30.0_1
  * gstreamer1-1.16.2_1

### Expected behavior

Playing of youtube videos with webkit2gtk works.

### Actual behavior

* Playback hangs after fast forwarding.
* Playing multiple youtube videos simultaneously is broken.

### Steps to reproduce the behavior

1. Execute `/usr/libexec/webkit2gtk-4.0/MiniBrowser`
2. Go to www.youtube.com
3. Choose any video and start playing
4. Fast forward to an arbitrary time point

### Notes

* The same behavior can also be observed with surf.
* **It might be a gstreamer issue (which is used for youtube streaming) and not an webkit2gtk one.**
* Updating webki2gtk to version 2.30.2 didn't help.