Using AvalonMaster on an inout struct type drives X or Z on request signals until a read/write command is issued

[egk696]

I have a bus converted into a single inout record and instantiated the object as follows:
avmm_csr0 = AvalonMaster(dut.csr0_slave_bus_io, "", dut.pcie0_clk)

However, when simulating the above, I get 'X' on address and writedata signals of the struct, until a read/write command has been issued. I believe X's should not be there. Am I using AvalonMaster wrong or is this a bug or is it expected? Thanks.