[JakeBrushwood]

Have got a New SL2 2020 ARC PRO set for my Grandchildren! BOTH cars worked first time after assembly. 
However, after EVENTUALLY installing a working ARC PRO app ONE of the cars 'countdowns'  the laps OK (on both lanes) the other car doesn't countdown on either lane. I'm thinking it's the connection of that car with the track - ANY IDEAS  OR HOW TO CORRECT?  Swap  'braids' between cars maybe?

[woodcote]

If I've got this right...

• Both cars are driving round the track okay when the app is in use (green light on powerbase) and when it is not connected (red/orange light).
  
• Both cars change lanes okay?
  
• One car counts laps no problem in the app, the other doesn't count laps.
  

Lap counting in ARC Pro depends on some hardware and some software factors - my hunch is it's how you have the app set up (ie software). It's all here: slotracer.online/arc-pro-guide/preparation

Just for info, which two cars do you have with the set? And which car counts laps and which car doesn't?