The beta version currently available is the same as the stable version. There are no known issues at the moment with the touchlink feature.
Please make sure your remote touches the bridge when using touchlink, this is very important. Also remove all other lights from power. You can find the instructions with a video here: How to connect IKEA TRÅDFRI smart controls to a Philips Hue bridge?
In case you are still interested in the beta, see the following: Join the beta - Try new features before they are officially released