This excerpt from the user's manual can explain the problem of your switch.
"... - This washer-dryer is equipped with a program "Self-cleaning" of the internal parts which must be carried out with the drum completely empty. Laundry detergent (in a quantity equal to 10% of that recommended for lightly soiled laundry) or special additives for cleaning the washer-dryer may be used as additives in the washing programme. It is advisable to run the washing programme every 40 washing cycles. It will be dyed after the end of the programme. Turn the programme selector to its original setting. The "Locked" indicator The safety lock flashes after the childproof lock is activated...."
WHIRLPOOL AWZ 8279 WP, SIEMENS WT44W3D2, WT 44 W 3 D 2, WHIRLPOOL FT M11 8X3B IT, 869991584020, WHIRLPOOL FT M10 81Y EU, , WHIRLPOOL HDLX 80410, SIEMENS WT7HY680CH, WHIRLPOOL HSCX 80316, BEKO DTKCE80021W, DTKCE80021W
Manufacturer's part price is £124.78 Discount for bulk (starting at 10 units), £120.67 per unit
This manufacturer part is recomended by BEKO, which gives it a 10/10 rating.
This spare part is recommended for your BEKO DTKCE80021W dryer .
All spare parts are new and come with two years warranty
① Carefully check your BEKO dryer's product number
② Start search
Here are examples for partial reference for dryer :
Where to find the reference?