The miliseconds timing isn’t respected from Symfonium. This causes a massive desync on certain songs where the lyrics changes very fast. Jellyfin itself does respect the correcr timing which means that it switches to the next lyrics at the exact timing while Symfonium skips to the next line way too early
They are respected, but Symfonium also add a small timing adjustment to take in account all the delays that occurs on some devices, as it’s better to be a little in advance than late.
With that said your logs are playing from an offline cached file, so I do not see the lyrics that Jellyfin did return
Please make a video and play song not from offline cache to see the data from Jellyfin and what the delay do on your device. (So provide logs corresponding to that video)
I did exacrly what you wanted and have the same issue. I uploaded the logs and a video with Symfonium and Jellyfin where you can see the difference pretty clearly https://file.io/iRqGHNEK5S5a