Checksum on Loopback adapter

I installed NPcap 1.79 some days ago. And it works fine. Thanks!
Except that I noted in tcpdump.exe (or windump.exe) all the received IP (?) packets are printed with a cksum 0:

WINDUMP.EXE: listening on \Device\NPF_Loopback, link-type NULL (BSD loopback), snapshot length 262144 bytes
IP (tos 0x0, ttl 128, id 58580, offset 0, flags [none], proto ICMP (1), length 60, bad cksum 0 (->57ea)!)
    127.0.0.1 > 127.0.0.1: ICMP echo request, id 1, seq 36, length 40
IP (tos 0x0, ttl 128, id 58581, offset 0, flags [none], proto ICMP (1), length 60, bad cksum 0 (->57e9)!)
    127.0.0.1 > 127.0.0.1: ICMP echo reply, id 1, seq 36, length 40
IP (tos 0x0, ttl 128, id 58582, offset 0, flags [none], proto ICMP (1), length 60, bad cksum 0 (->57e8)!)
    127.0.0.1 > 127.0.0.1: ICMP echo request, id 1, seq 37, length 40
...

I'm not sure if this is a feature or short-coming of NPcap or not. Or windump? I cannot imagine.
I have not enabled checksum offload of my physical networks adapters
(if that would make a difference. I think not).

I also see these cksum 0 for loopback traffic inside the Thunderbird email client (when I press About | Check for updates etc.).

To Reproduce

In a Windows-shell (like CMD, yuk!):

start c:\Windows\system32\ping.exe -n 1000 -4 127.0.0.1
windump.exe -vtn -i \Device\NPF_Loopback

and notice all the cksum 0 texts. Seems only the IP-checksums are 0 and the TCP/UDP check-sums are OK.

Expected behavior

I want checksum to appear as they are sent by ping.exe, Thunderbird or whatever.

Screenshots

A start windump.exe --color -vvtni \Device\NPF_Loopback followed by a ping -n 3 -4 127.0.0.1 look like:

• Windows version: Win 10. Build 19045, Home. 22H2 (OS-build 19045.3996)

Reproduce the report with ping.exe and windump.exe on \Device\NPF_Loopback, then trace the NPcap loopback capture path responsible for the IP checksum field. Compare captured loopback packets with the checksum expected from the original ping traffic; done means loopback captures no longer report IP checksums as zero when the packets contain valid checksums.