I would seek legal advice but I would think as they are tenants they are bound by the bylaws so they can’t cry squatters rights.
Squatters are not tenants, so the tenants are in breach of the bylaws (which ones I don’t know as I do not know what bylaws apply), so a notice to comply with the bylaws, if that doesn’t work, then mediation, if that doesn’t work then adjudication.