Failure to send token from ICON chain to BSC chain using 'transfer' method of BTS contract on testnet.

[FidelVe]

Trying to send btp-0x2.icon-bnUSD token from ICON chain to BSC chain results in failure.

here is the tx address:
https://tracker.lisbon.icon.community/transaction/0x421a5f0d5f923704539896856017cac4334763c5806722073fd9ab96ef4b6a19

these are the params used:

{
	"method": "transfer",
	"params": {
		"_coinName": "btp-0x2.icon-bnUSD",
		"_to": "btp://0x61.bsc/0x4DeD312eB774B9828665448C55Faa8AE15353E56",
		"_value": "0x6da27024dd960000"
	}
}

the error is the following:

FRAME[2] INVOKE done status=Reverted(0) msg=E0032:InSufficient Usable Balance steps=552956

I have verified that I have enough balance of token btp-0x2.icon-bnUSD on the wallet.