[Modder question] Randomly missing dialogue topics in CK editor?

[DeepBlueFrog]

I am experiencing a weird issue with CK editor.

 

From time to time, a whole branch of dialogue and related topics just go missing in the editor.

 

If I look at the dialogue view, the graph layout is empty. 

In Dialogue topics, the branch is there but the topics are missing.

 

However, the topics are still there in-game.

 

I tried refreshing the SEQ file and, after many reloads, the missing dialogue topics are visible in CK editor again, but then other topics are missing elsewhere.

 

Is that another example of flakiness in CK or is there something I can do to fix this?