Thermador Range Hood - buttons blinking and fan difficult to control

Oven Repair (including Ranges and Cooktops)
1

Thermador hood model HPCB36NS / 01
Control Box Bosch Hood Vent Control 9000699182
Button part: 9000809580 rev A Chimney Hood Control

The range hood started changing clicking buttons to on / off and turning on the high fan speed intermittently. You can turn it off and 30 seconds later will restart.

Buttons activate them selves, but all work (at least for a few seconds).

Suggestion to replace the control box or the buttons?

Both are fairly pricey parts.

Thanks