Losing POWER and SPEED Sensor permanently in Sessions Tacx Flow Smart T2240

Since 2 Month iii using 

Tacx Flow Smart T2240 

Im always losing POWER and SPEED Sensor during Sessions. The firmware is on latest.

Sometimes the POWER Sensor going up to over 400W for 1 or 2 Seconds ii never can do 

this by myself, but this is not so often then losing the Sensors.