picture is too late to be displayed, playback way too early & pulse audio output debug: underflow

[postcd]

Hello,

ffmpeg was used by Lossless-cut to merge video fragments and resulting file was also converted by ffmpeg using libx264 -vsync 2
And VLC plays the file but at the point where fragments was joined pause for many seconds and then resumed. MPV player on other hand plays fine without pause.
Here is the output at the time of playback being temporarily stuck and resume:

[00007f4f00051a30] main filter warning: dropping pictures
[00007f4f00051a30] main filter warning: dropping pictures
[00005628df48c6b0] pulse audio output debug: underflow
[00007f4f0804eb70] main video output warning: picture is too late to be displayed (missing 20196 ms)
[00007f4f0804eb70] main video output warning: picture is too late to be displayed (missing 20154 ms)
[00005628df48c6b0] main audio output warning: playback way too early (-21262875): playing silence
[00005628df48c6b0] main audio output debug: inserting 1020618 zeroes
[00007f4f0804eb70] main video output warning: picture is too late to be displayed (missing 20362 ms)
[00007f4f0804eb70] main video output warning: picture is too late to be displayed (missing 20321 ms)
[00007f4f0804eb70] main video output warning: picture is too late to be displayed (missing 20238 ms)
[00007f4f00051a30] main filter warning: dropping pictures
[00007f4f00051a30] main filter warning: dropping pictures

full output is here

Can you please suggest how to re-encode the file with high chance that VLC will play the file without issue? I am using ffmpeg for the task. Thank you

Similar: https://github.com/mifi/lossless-cut/issues/1245