Truma Combi knob hard to press and wont show Icons

[robbiegee]

Have a 2019 Winnebago Travato 59K. Used the Truma about 2 times. On the last time we had no hot water. Getting the icons got harder and harder until button would not go in. Do I need to buy a new expensive Control Panel? Can I lube the knob with silicone? Any help Wii be appreciated. Im elderly and cold showers are not fun. Thanks in advance.