Mine turned out to be the battery wasn’t clicked in properly. When the shop did the handover they insisted on showing me how the battery came out but they mustn’t have clicked it in properly.Bombie,
Don't want to get your hopes up, but:
Picked my 2023 Whyte e160 up last weekend. Didn't have time to tune suspension or set up cockpit. Couple of local rides, no issues. Started tinkering with cockpit/suspension few days later. LED remote wasn't where I wanted it so - unplugged the cable, moved LED mount. Plugged cable back in. Attempted to turn on - same issue as you - leds chase up and down but no start up (or connection to Flow app). Realised it must be due to not plugging cable in correctly, took a closer look, hadn't pushed it back in until it 'clicked' into place. It takes a fair bit of force.
Have you had yours apart and now have the same issue possibly? I suspect the blue leds chasing up and down but then switching off could indicate a connection issue with the LED module. On the underneath of the cable is a white mark which lines up with one on the the port, take care and check it hasn't somehow been caught and loosened. Hope this helps bud.
Tower
Edit: apologies, just spotted this was July, not August. Presumably you got it sorted.