Sold 2 wheeler years ago, but the RC list still shows me as 1 of the 2 owners

I had sold a barely used (few weeks) scooter in Feb 2018. I recently (Sept 2021) checked the registration details of the vehicle in Vahan portal and noticed that both the buyer's and my name are visible as the owner with the status of both as active under the "RC Status" heading. The buyer had registered in a different RTO - North Bangalore while my registration had been done in South Bangalore. Furthermore, strangely the registration date next to his name matches mine which is on Dec 2017, although he had only purchased it in Feb 2018. During the sale, the buyer had insisted that he would complete all the transfer formalities so I do not have the copy of form 29 or 30 nor did I intimate the RTO. These are the only documents I currently have: Delivery note and the following copies - buyer's driving license, insurance policy, road tax certificate, booking form, tax invoice What can I do now to remove my name from the RC list of owners as an active owner in the RC Status list?