When I cast an online content such a live football match to my Android TV (with Ace Cast installed) it is all the time prebuffering 0%.
If you know how to solve this I would be grateful
Please, be more specific - did you run Ace Stream on Android TV device at least once and allow app permissions (if any)?
Did you check how work any CID/.torrent/.acelive file directly on the Android TV device?
Did you check same CID/.torrent/.acelive file on the device, from which you attempt to cast?