In China, real estate is real estate, and its ownership is based on registration.
For example, the owner of the property right certificate is not you, but your family (even your spouse). If there is the signature of the owner, then the transfer is legal and protected by law.
If the owner's name on the real estate license is you, you must sign or authorize the transfer. If you don't sign or authorize the transfer, the transfer procedure is invalid. You can go to court and ask for confirmation of your property rights.
Even if you sign the contract, the other party has paid the money. As long as you are willing to compensate the other party for the loss and haven't signed the transfer, the property right of the house still belongs to you. The entry into force of the contract does not mean the transfer of property rights. But if you are unwilling to pay compensation or sign, the other party may sue you, and finally go through the transfer formalities according to the court's decision)
If the real estate license is owned by you and your family, it is invalid for one party to change the property right without the consent of the other.
Of course, if the house is still involved in mortgage or is judged by the court because of other debt relations, the other party can go through the transfer formalities without your signature according to the court judgment.