In most cases yes, you have to wait a little while before the messages appear, the time for Web to Confirm them (well yes it can't do everything at the same time!😵) However, maybe your messages had content that Web considers harmful, inappropriate to the site, etc. but here I can't say anything; you can always ask customer service but anyway, there's always a good reason for some messages not to be validated (abuse, advertising, etc). I hope I have answered your question 😃
