If you are on Free Trial,
You can post up to 5 job postings but after 30 days all the job postings will be automatically closed. In order to keep the job postings open, you'll need to upgrade to premium plans before it expires.
If you are on Starter plan and above,
There are no limits in the number of job postings or the time of job postings being published.
If you are still having trouble, contact Wantedly Customer Relations Team from here!