Ardour5.8 randomly shutdown a piste

Hello,
I am French and my English is not very good, I apologize in advance.

I’m not sure about the best way to explain my problem.
I have several tracks, some mono, other stereo, all are flac files.
My files are over an hour (audio file of a video sound).
When I play them, or I export the result of the mix, one of the tracks, or one of the channels of the stereo track, this blocks.
Most often it is the left or right channel of the stereo track, but sometimes it is a mono track. This problem this product “at random” (I did not find a reliable cause)
More often than not, this “blocking” intervenes during export. Arrived at 1/4 of the end, the stereo track loses its left or right channel, and it is unbalanced during the last quarter of the mix.
I’m wasting time with this problem. The temporary solution is that I went back to Ardour4 which seems not to have the problem.
Am I the only one to encounter this problem? is there a solution ?
Do you need more details? Which ones?

Thank you in advance.

Do you have plugins on this session? Does it still happen if you make a copy of the session and remove all plugins?

 Seablade

Yes I have some calf plugin (2 or 3 per track). And yes I had already tried without any plugin: same problem.
I just performed a morning test. I also encounter the problem under ardour4 finally. But I tried something else, I converted to wav the source of my stereo track that was in flac, and there everything woks. I will do the same with ardor5.8, and if it works, then the problem could come from the management of the stereo flac

I was able to export my mix.
I converted my tracks flac into wav, and I was able to successfully exported it all in wav.
The problem seems to be related to the flac format on my pc.
It’s a shame the flac format is still much smaller.