The buyer can’t be registered as the owner of the shares in Freetrade’s share register until HMRC confirms that the buyer has paid share transfer tax. This can take a number of weeks.
In the meantime, the shares that you owned until 1 April 2025 will still show in the register. However, this does not mean that you own them and you cannot sell, transfer, pledge, lend or otherwise deal with them in any way.