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.
{"sequence", RPCArg::Type::NUM,  "depends on the value of the 'replaceable' and 'locktime' arguments", "The sequence number"},
                                },
                                },
                        },
                        },
                    {"outputs", RPCArg::Type::ARR, RPCArg::Optional::NO, "a json array with outputs (key-value pairs), where none of the keys are duplicated.\n"
                            "That is, each address can only appear once and there can only be one 'data' object.\n"
                            "For compatibility reasons, a dictionary, which holds the key-value pairs directly, is also\n"
                            "                             accepted as second parameter.",
                        {
                            {"", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED, "",
                                {
                                    {"address", RPCArg::Type::AMOUNT, RPCArg::Optional::NO, "A key-value pair. The key (string) is the bitcoin address, the value (float or string) is the amount in " + CURRENCY_UNIT},
                                },
                                },
                            {"", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED, "",
                                {
                                    {"data", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "A key-value pair. The key must be \"data\", the value is hex-encoded data"},
                                },
                                },
                        },
                        },
                    {"locktime", RPCArg::Type::NUM,  "0", "Raw locktime. Non-0 value also locktime-activates inputs"},
                    {"replaceable", RPCArg::Type::BOOL,  "false", "Marks this transaction as BIP125 replaceable.\n"
                            "                             Allows this transaction to be replaced by a transaction with higher fees. If provided, it is an error if explicit sequence numbers are incompatible."},
                },
                RPCResult{
                            "  \"psbt\"        (string)  The resulting raw transaction (base64-encoded string)\n"
                },
                RPCExamples{