I have a RPB2 and I am using the Realtek WIFI dongle. When the dongle stopped being supported I had to reinstall the kernel 4.14.78-4. It has worked fine until now. However, today I have updated the system to the latest version and a new kernel version has been installed, which has become the new default. How can I change the default kernel to the old one? I guess it is something simple but I do not really know where to start.