Joplin (iOS, on iPad) seems to crash and delete my current file

Hi,
I just have a serious issue; I worked on a file I created two hours ago, on my iPad version of Joplin: the app suddenly became white and blank (while I was writing using the dark theme), and nothing happened after. I had to kill the app twice to make it work again, but in the meantime the file I wrote two hours of important notes disappear totally: I can’t see its trace nowhere, even in the Journal (I’m not really able to understand what I read in the Journal, though). Is there a possibility to recover the file ? The other synchronized instances of Joplin (on MacBook and iPhone) can’t help too; the mac version show some files created in the meantime, but only with metadata, not a file with a text inside…