Easync does not update in real time:
In particular, additions are reflected quickly but suppressions/deletions update more slowly, so right after you suppress listings the system may still count them as active and show a "no listing limit / limit reached" error that blocks you from listing more, even though you appear to be under your limit.
The count normally re-updates within the day, so the usual fix is to wait for it to sync and then load your products again from the Add Products section.
If it still won't update or the error persists, send support the Easync listing/request link for the affected batch and they'll escalate it to the tech team.