Loss of data by writing posts and saving them

Hi guys,

i already had that problem before but cant find it anymore here.

i just wrote 3 hours on an article and always was saving intermitend to make sure i dont lose any data. at one of the saves it displayed all the sidebars like blog images, blog format where extended. so i hit save again to reload the side and after that all the content was gone.
Just headline and all the options in the siddemenu like blog image, blog format stayed. everything elsw as gone. I dont know what caused the issue. i was able to save and save for a lot of times but just at that one point it showed me all the sidbars extended and that was it.

so far everything is working but this issue is a big issue for me. Probably i should use strg + c to copy everything before saving. Maybe you have any ideas....