I don’t know how correctly I understood your text, but on my laptop, when I write a post, press the back button, and then click again on the page to print the post, everything is saved. Maybe the problem lies when using mobile gadgets. I deliberately tried to do this, but maybe this happens after a pause.
Yeah it happens alot to me when I was starting up the forum and yeah it mainly occur on the mobile and the browser involved also matters. The only trick I use now is just to save the whole text am typing by simply clicking preview button before posting so that its going to be saved manually before I actually post my text, if not you will this very annoying when it eventually happens especially after typing a very long text then the whole thing just wipes out.