This could have to do with what you are using to input the notes you are playing in ARCADE.
When using the mouse, the data isn't sent to your DAW as MIDI Note data and therefore won't be recorded into the timeline, so this may be the reason you don't see it.
If you'd like to use your keyboard please make sure it's a MIDI keyboard with a USB cable that you can connect to your laptop. Then, it will automatically sync with ARCADE. So each Kit in ARCADE contains two octaves or 24 keys. These are spread out from the C2 to C4 range on your MIDI keyboard. To play and record a Loop, press one or more keys in the C2 to C4 range. Please make sure to play and record inside this range.
If you don't have a MIDI keyboard, don't worry. You can still use your computer keyboard!