@evelyb30
Not sure if I can shed any light, other than to confirm it has happened to me (and many others), usually just after submitting a lengthy post.
If I see that red band while composing a post, I generally open up a community post in another browser tab and refresh it to make sure I am still signed in (or to sign in again if necessary). Then I go back to finish the original message, and copy the entire message to the clipboard (just in case it is lost). And then try to post. Most of the time that seems to work, but sometimes I have to back up, paste in the message again, and post again.
If I forget to copy the message and run into problems after attempting to post, sometimes I can go back to the original posting screen using the back button rather than the text link and see a teal band indicating that I have saved content (once I am signed in), and I am offered the option to load or discard it; that saved content may not be completely up to date, though.
Latest saved drafts can also be found at the bottom of your Community profile page if you get lost after trying to post.
If you are getting repeated sign-in messages in the Community boards, you might want to make sure your browser is set to accept (and keep) cookies, and perhaps manually erase your eBay cookies if you think there is a problem. Then go to your Account Site Preferences, and make sure the box at the bottom to keep you signed in to the community boards is checked, and hit apply.
