Incorrect Operand AccessMode parsing

[windgodm]

Incorrect operand parsing:

x64 assembly: xor r11b, 0
in binary: 41 80 f3 00

Here is a part of test code:

DISASM infos;
int len;
BYTE buf[4] = { 0x41, 0x80, 0xf3, 0x00 };
// init
memset(&infos, 0, sizeof(DISASM));
infos.EIP = (UINT64)buf;
infos.VirtualAddr = 0;
// disasm
len = Disasm(&infos);
cout << infos.Operand1.AccessMode << endl;

I expect the result to be infos.Operand1.AccessMode = 3 (3 = READ | WRITE)
But it print 2 (2 = WRITE)

I check xor rcx, Imm, the result is 3, which means rcx will be read and than write.
But when it disasm xor r11b, Imm, the result is 2, means r11 only be write.
I think the result should be the same as the former as 3.