If the situation is misrepresented by the real estate agent or the previous owner, not the owners corporation, then that is not your problem.
The EC could write to the agent to advise that their ad is inaccurate.
We had a good experience with a selling agent a few years ago. We let them know that a fence was not approved or approvable (wrong style and enclosing part of the common property) and the new owner would be required to remove it. The agent explained to all prospective purchasers who looked serious. The new owners promptly removed the fence.
I think most agents try to get it right and yours might have been misled or misunderstood advice from their clients.