No attempt to load MOK with fedora's shim-15.4-4 and httpboot

Greetings,

I'm trying to set up custom netboot with secureboot and HTTP. I'm setting dhcp bootfile to: "http://servername/path/BOOTX64.EFI" which is the shim.
Start the VM, it loads the shim. Then shim tries to load "http://servername/path//grubx64.efi". If I put a custom selfsigned binary in there, then it obviously fails to load and shim displays "access violation [OK]". But once I press OK once, it displays it again, and once I do it once more, it prints a few lines about "start_image blah security violation" and exits. It's almost like https://github.com/rhboot/shim/blob/main/shim.c#L1122 here instead of the MOK_MANAGER it tries to load second_stage again
If I tcpdump all network traffic, I see that when I press OK it actually tries load grubx64.efi again, not mmx64.efi. In fact, it never tries to load anything besides grubx64.efi. I tried renaming mmx64 to grubx64 and it successfully loads it.

So my questions are:

• is it a known issue with known fix?
• is there newer signed shim that I can test that might not have this problem?

Thanks

Start with shim.c around line 1122 and reproduce the Fedora shim-15.4-4 HTTPBoot flow described here. Use tcpdump to compare requests for grubx64.efi and mmx64.efi after the access-violation prompt; done means identifying why MOK_MANAGER is not attempted and confirming a fix or documenting the limitation.