Error with PClap Counter and Oxigen

Hi there,
don't know If I'm right here, but the topic fits. I just need another bit of support here for counting laps. I race at home on Ninco with complete oXigen electronis and PC-LapCounter.
When I generate a track call and a cars rolls over the lane changers, PCLC sometimes recognises this as a lap. This gets shown with the +1 symbol. The only mechanism that catches that is minimum laptime. But there are circumstances like a slow first lap after track call where you can get a additional lap.
The controller does't show the "L" sign when this happens.
Is there any possibility to get this figured out, or has anybody the same behaviour?

kind regardy, Tristan.

Hi,
Thanks a lot it your replies! Yes, I only use C chips. I havent looked for the cars itself in special, but i will keep an eye on it. The car I know that does it some times has now a new sensor. 3 times 10 minute race was without fault.
PCLC has both yellow flag to slow the cars down and track call to stop completely. I use the complete stop, initiated by a deslotted car.
Kind regards Tristan