If any submission disapeared of your dashboard, it was archived due to:
1- lack of current interest to be published by this journal (for recent submissions).
2- too much time with no reviewing action by referees, in deference to authors (for delayed submissions). In this case, authors can adequate the submission to the new guidelines and resubmit to the journal, if so.
We are having problems with our new tracking system regarding communication between authors and editors. So, some problem can occur for a while.
Thanks for your comprehension and interest in publishing with us.