When the newly introduced `"maxfeerate"` option is not passed, the default fee rate is interpreted as an absolute amount. However, when it is passed, it is interpreted as a fee rate. Thus, the rpc will return different results when the value is explicitly set to the default.

See

https://github.com/bitcoin/bitcoin/blob/536590f358dc3d3e5821eba7f1009452ea93b205/src/rpc/rawtransaction.cpp#L797-L807

I think we should change it back to an absolute value in BTC (not a feerate)

This was changed to a feerate by @kallewoof, so ping him to see if there was a specific reason to switch.
{
    
    
    
    
    
    TxToUniv(tx, uint256(), entry, true, RPCSerializationFlags());
    if (!hashBlock.IsNull()) {
        LOCK(cs_main);
        entry.pushKV("blockhash", hashBlock.GetHex());
        CBlockIndex* pindex = LookupBlockIndex(hashBlock);
        if (pindex) {
            if (::ChainActive().Contains(pindex)) {
                entry.pushKV("confirmations", 1 + ::ChainActive().Height() - pindex->nHeight);
                entry.pushKV("time", pindex->GetBlockTime());
                entry.pushKV("blocktime", pindex->GetBlockTime());
            }
            else
                entry.pushKV("confirmations", 0);
        }
    }
}
static UniValue getrawtransaction(const JSONRPCRequest& request)