Just a few checks... let the BCR charge up a bit. Also make sure the teather from the tender is seated in the receptacle on the locomotive. You may want to disconnect the teather and reconnect.
Try doing a factory reset on the engine if you can find the engine name/number on your controller. It will delete the engine in the process and then you can re-enter the locomotive.
I am no expert, I am just relating things that have worked for me in the past...
Tom