It's a known issue that is still under investigation, but one of the possible lead could be that it is linked to the sensors of the hand that may detect contact when there is none. This is due to a hardware limitation of the product that is not corrected yet.
However, have you tried going back to 2.8.6 (I assume you were using this version of NAOqi before 2.8.7 ?) to see if it is working again ?
You can go to the ADE (https://cloud.aldebaran-robotics.com/) and set a manual update to 2.8.6 :
You will then need to downgrade your NAO through the webpage.