Hi Lonborghini - welcome to the forum and a Happy New Year to you!
As gorp said, check if everything works okay out of the app first. I suspect that you need to check and double check that the cars are connected to the colour you think they are. The IDs are different from previous digital powerbases to ARC Pro, so you will need to re-connect them to ARC Pro. Also make sure the controllers are connected. Otherwise swapping over the powerbases (what you describe as the 'power base mod') should work fine.
The biggest learning curve with ARC Pro is what I call 'the rule of the three colours'. The colours on the powerbase, controller and of the driver/car in the app must all match. The default colours are red and green, so I always start with those and then add blue, yellow, orange & white in that order. Each controller should be connected to a colour on the powerbase & you also connect each car to a specific colour on the powerbase - these two processes are explained in the Quick Start Guide. Connect a car to red and you control it with the red controller - whether the app is on or off.
The third colour connection is to match the car ID (the colour on the powerbase the car is connected to) with the background colour of the driver tile in the race set-up menu of the app. This is the sliver of colour to the top and left of the tile. Set-up a car/driver on the red tile (default = Driver 1) and the powerbase lap sensors will search for the car connected to red on the powerbase and display data for it in the app. If you set up the car on another colour in the app, the red controller will still control the car connected to red, but no data will be recorded. It will seem as if the app isn't counting laps - however, it hasn't been set up to 'see' the car. Remember, all three colours must match.
I also see that none of you android devices are on the campatible device guide. You could browse the thread to see if there is anything discussed about the Asus or the S7. The thread is here: https://www.scalextric.com/uk-en/forum/arc-app-device-compatibility/
I hope that helps.