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 1803, Build 17134
. . . the presumption of innocence, while essential in the legal realm, does not mean the elimination of common sense outside it. The willing suspension of disbelief has its limits, or should.
~ Ruth Marcus, November 10, 2017, in Washington Post article, Bannon is right: It’s no coincidence The Post broke the Moore story