I thought about posting the text but it looks off/not formatted for easy reading..
pi@raspberrypi:~ $ dig -x 2001:8a0:574c:e301:30a0:4f96:b62b:c768@192.168.1.88 ; <<>> DiG 9.11.5-P4-5.1+deb10u1-Raspbian <<>> -x 2001:8a0:574c:e301:30a0:4f96:b62b:c768@192.168.1.88 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 46842 ;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4010 ;; QUESTION SECTION: ;88.1.168.2001:8a0:574c:e301:30a0:4f96:b62b:c768\@192.in-addr.arpa. IN PTR ;; AUTHORITY SECTION: in-addr.arpa. 2391 IN SOA b.in-addr-servers.arpa. nstld.iana.org. 2020061019 1800 900 604800 3600 ;; Query time: 156 msec ;; SERVER: 192.168.1.254#53(192.168.1.254) ;; WHEN: ter jun 30 12:31:55 WEST 2020 ;; MSG SIZE rcvd: 161
pi@raspberrypi:~ $ dig -x 2001:8a0:574c:e301:4d99:d1e0:7c76:4db3@192.168.1.88 ; <<>> DiG 9.11.5-P4-5.1+deb10u1-Raspbian <<>> -x 2001:8a0:574c:e301:4d99:d1e0:7c76:4db3@192.168.1.88 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 40517 ;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4010 ;; QUESTION SECTION: ;88.1.168.2001:8a0:574c:e301:4d99:d1e0:7c76:4db3\@192.in-addr.arpa. IN PTR ;; AUTHORITY SECTION: in-addr.arpa. 1717 IN SOA b.in-addr-servers.arpa. nstld.iana.org. 2020061019 1800 900 604800 3600 ;; Query time: 212 msec ;; SERVER: 192.168.1.254#53(192.168.1.254) ;; WHEN: ter jun 30 12:35:51 WEST 2020 ;; MSG SIZE rcvd: 161
Also I checked on the router again and DHCP is off.