Description of problem:
source and destination address is omited in arptables -L and arptables-save commands.
nft ruleset is identical to one produced on x86_64 so it seems to be just presentation issue (and save issue as well)

Version-Release number of selected component (if applicable):
iptables-arptables-1.8.2-8.el8.s390x
kernel-4.18.0-67.el8.s390x

How reproducible:
always

Steps to Reproduce:
[root@ibm-z-118 arptables-smoketest]# arptables -N mychain
[root@ibm-z-118 arptables-smoketest]# arptables -A mychain -s 1.2.3.4 -j ACCEPT
[root@ibm-z-118 arptables-smoketest]# arptables -A mychain -s 1.2.3.4 -d 255.255.255.255 -j ACCEPT
[root@ibm-z-118 arptables-smoketest]# arptables -A mychain -s 1.2.3.4 -d 255.255.255.255/25 -j ACCEPT
[root@ibm-z-118 arptables-smoketest]# echo $?
0
[root@ibm-z-118 arptables-smoketest]# nft list ruleset
table arp filter {
	chain INPUT {
		type filter hook input priority 0; policy accept;
	}

	chain OUTPUT {
		type filter hook output priority 0; policy accept;
	}

	chain mychain {
		arp htype 1 arp hlen 6 arp plen 4 @nh,112,32 16909060 counter packets 0 bytes 0 accept
		arp htype 1 arp hlen 6 arp plen 4 @nh,112,32 16909060 @nh,192,32 4294967295 counter packets 0 bytes 0 accept
		arp htype 1 arp hlen 6 arp plen 4 @nh,112,32 16909060 @nh,192,32 & 4294967168 == 4294967168 counter packets 0 bytes 0 accept
	}
}
[root@ibm-z-118 arptables-smoketest]# arptables -L -v
Chain INPUT (policy ACCEPT 0 packets, 0 bytes)

Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)

Chain mychain (0 references)
-j ACCEPT -i any -o any --h-length 0, pcnt=0 -- bcnt=0 
-j ACCEPT -i any -o any --h-length 0, pcnt=0 -- bcnt=0 
-j ACCEPT -i any -o any --h-length 0, pcnt=0 -- bcnt=0 

[root@ibm-z-118 arptables-smoketest]# arptables-save
*filter
:INPUT ACCEPT
:OUTPUT ACCEPT
:mychain -
-A mychain -j ACCEPT --h-length 0
-A mychain -j ACCEPT --h-length 0
-A mychain -j ACCEPT --h-length 0

Actual results:
-s IP -d IP are missing in rules

Expected results:
# arptables-save
*filter
:INPUT ACCEPT
:OUTPUT ACCEPT
:mychain -
-A mychain -j ACCEPT -s 1.2.3.4
-A mychain -j ACCEPT -s 1.2.3.4 -d 255.255.255.255
-A mychain -j ACCEPT -s 1.2.3.4 -d 255.255.255.128/25

Additional info: