Is it illegal for property employees to collect property fees privately to help owners pay?

It is not illegal as long as the property employees charge the owners according to the actual amount payable and hand it over to the company in time on the premise of mutual willingness.

Article 41 of the Property Management Regulations stipulates that the owner shall pay the property service fee in accordance with the property service contract. If the owner and the user of the property agree that the user of the property shall pay the property service fee, the owner shall bear joint and several liability from the agreement. Property that has been completed but has not been sold or handed over to the property buyer shall be paid by the construction unit.