This same problem has happened to me several times when I guess that I got a bit too wordy making a detailed response to a post. I have tried to remember to use ShuttlePilot Eric’s ‘90s trick of saving a copy before hitting the post button, but sometimes I forget until the microsecond after I hit the “submit reply” button
It is very frustrating and more than once I have given up in disgust and not bothered to recreate my lost post. It doesn’t seem to happen if I start my reply with reference to a “quote” from another member, but that may just be a coincidence. I don’t understand why the program can’t retain what you have written, while redirecting you to log in again,.. using my Mac, the “redirect” takes me to a blank screen after I “sign back in”. I wish this problem could be fixed, it has rarely happened to me on any other forum.