All I can suggest is that you report this on the BleepingComputer Announcements, Comments, & Suggestions forum.
I know that this has been brought up before, and not just by you, and has been (and possibly still is being) looked in to. The last report I had is that there has been no success in replicating this event nor in figuring out what it is that triggers it. Until or unless both can be done fixing it is just not going to happen. You can't fix what you can't reproduce.
I would suggest you pay very careful attention to what you may be doing just before hitting the "Post" button each time you post to see if you can determine any pattern. You can also certainly try an alternate web browser, too, but I do not think this has been limited to any single browser.
I've had it happen on a couple of occasions but it's been quite a while since the last occasion.
Brian AKA Bri the Tech Guy (website in my user profile) - Windows 10 Home, 64-Bit, Version 1809, Build 17763
Travel is fatal to prejudice, bigotry, and narrow-mindedness, and many of our people need it sorely on these accounts. Broad, wholesome, charitable views of men and things cannot be acquired by vegetating in one little corner of the earth all one's lifetime.
~ Mark Twain