I can tell you that I tried so many times to reinstall unbound so maybe it’s a bit dirty?
I reboot the system but i think is the same 
root@DietPi:~# ss -tulpn | grep LISTEN
tcp LISTEN 0 50 0.0.0.0:445 0.0.0.0:* users:(("smbd",pid=1251,fd=48))
tcp LISTEN 0 4096 127.0.0.1:42143 0.0.0.0:* users:(("casaos-local-st",pid=1302,fd=9))
tcp LISTEN 0 4096 127.0.0.1:38849 0.0.0.0:* users:(("casaos-gateway",pid=950,fd=7))
tcp LISTEN 0 128 0.0.0.0:9091 0.0.0.0:* users:(("transmission-da",pid=1469,fd=14))
tcp LISTEN 0 80 127.0.0.1:3306 0.0.0.0:* users:(("mariadbd",pid=1383,fd=20))
tcp LISTEN 0 511 127.0.0.1:6379 0.0.0.0:* users:(("redis-server",pid=1312,fd=7))
tcp LISTEN 0 50 0.0.0.0:139 0.0.0.0:* users:(("smbd",pid=1251,fd=49))
tcp LISTEN 0 4096 127.0.0.1:36971 0.0.0.0:* users:(("casaos-app-mana",pid=1205,fd=8))
tcp LISTEN 0 4096 127.0.0.1:44811 0.0.0.0:* users:(("casaos",pid=971,fd=11))
tcp LISTEN 0 4096 127.0.0.1:38923 0.0.0.0:* users:(("casaos-message-",pid=1113,fd=7))
tcp LISTEN 0 4096 127.0.0.1:6060 0.0.0.0:* users:(("crowdsec",pid=1450,fd=48))
tcp LISTEN 0 4096 127.0.0.1:35981 0.0.0.0:* users:(("casaos-gateway",pid=950,fd=10))
tcp LISTEN 0 4096 0.0.0.0:111 0.0.0.0:* users:(("rpcbind",pid=491,fd=4),("systemd",pid=1,fd=32))
tcp LISTEN 0 1024 0.0.0.0:80 0.0.0.0:* users:(("lighttpd",pid=1464,fd=4))
tcp LISTEN 0 4096 127.0.0.1:8080 0.0.0.0:* users:(("crowdsec",pid=1450,fd=13))
tcp LISTEN 0 128 0.0.0.0:51413 0.0.0.0:* users:(("transmission-da",pid=1469,fd=15))
tcp LISTEN 0 4096 127.0.0.1:39413 0.0.0.0:* users:(("casaos-user-ser",pid=1215,fd=7))
tcp LISTEN 0 1000 0.0.0.0:22 0.0.0.0:* users:(("dropbear",pid=596,fd=4))
tcp LISTEN 0 256 127.0.0.1:5335 0.0.0.0:* users:(("unbound",pid=868,fd=14))
tcp LISTEN 0 256 127.0.0.1:5335 0.0.0.0:* users:(("unbound",pid=868,fd=12))
tcp LISTEN 0 256 127.0.0.1:5335 0.0.0.0:* users:(("unbound",pid=868,fd=10))
tcp LISTEN 0 256 127.0.0.1:5335 0.0.0.0:* users:(("unbound",pid=868,fd=8))
tcp LISTEN 0 256 127.0.0.1:5335 0.0.0.0:* users:(("unbound",pid=868,fd=6))
tcp LISTEN 0 256 127.0.0.1:5335 0.0.0.0:* users:(("unbound",pid=868,fd=4))
tcp LISTEN 0 4096 0.0.0.0:3000 0.0.0.0:* users:(("docker-proxy",pid=1733,fd=4))
tcp LISTEN 0 5 0.0.0.0:8888 0.0.0.0:* users:(("rpimonitord",pid=1525,fd=5))
tcp LISTEN 0 4096 0.0.0.0:3001 0.0.0.0:* users:(("docker-proxy",pid=1712,fd=4))
tcp LISTEN 0 256 127.0.0.1:8953 0.0.0.0:* users:(("unbound",pid=868,fd=15))
tcp LISTEN 0 50 [::]:445 [::]:* users:(("smbd",pid=1251,fd=46))
tcp LISTEN 0 511 [::1]:6379 [::]:* users:(("redis-server",pid=1312,fd=8))
tcp LISTEN 0 50 [::]:139 [::]:* users:(("smbd",pid=1251,fd=47))
tcp LISTEN 0 4096 *:33293 *:* users:(("casaos",pid=971,fd=8))
tcp LISTEN 0 4096 [::]:111 [::]:* users:(("rpcbind",pid=491,fd=6),("systemd",pid=1,fd=34))
tcp LISTEN 0 1024 [::]:80 [::]:* users:(("lighttpd",pid=1464,fd=5))
tcp LISTEN 0 4096 *:81 *:* users:(("casaos-gateway",pid=950,fd=8))
tcp LISTEN 0 4096 *:8083 *:* users:(("AdGuardHome",pid=816,fd=9))
tcp LISTEN 0 128 [::]:51413 [::]:* users:(("transmission-da",pid=1469,fd=16))
tcp LISTEN 0 4096 *:53 *:* users:(("AdGuardHome",pid=816,fd=13))
tcp LISTEN 0 1000 [::]:22 [::]:* users:(("dropbear",pid=596,fd=5))
tcp LISTEN 0 4096 [::]:3000 [::]:* users:(("docker-proxy",pid=1740,fd=4))
tcp LISTEN 0 4096 [::]:3001 [::]:* users:(("docker-proxy",pid=1720,fd=4))
Ok now i fixed i reinstall all and i have only once
root@DietPi:~# ss -tulpn | grep LISTEN
tcp LISTEN 0 128 0.0.0.0:9091 0.0.0.0:* users:(("transmission-da",pid=9547,fd=14))
tcp LISTEN 0 4096 127.0.0.1:41225 0.0.0.0:* users:(("casaos-app-mana",pid=1142,fd=8))
tcp LISTEN 0 4096 127.0.0.1:40329 0.0.0.0:* users:(("casaos",pid=995,fd=8))
tcp LISTEN 0 80 127.0.0.1:3306 0.0.0.0:* users:(("mariadbd",pid=9434,fd=21))
tcp LISTEN 0 511 127.0.0.1:6379 0.0.0.0:* users:(("redis-server",pid=9371,fd=7))
tcp LISTEN 0 50 0.0.0.0:139 0.0.0.0:* users:(("smbd",pid=9358,fd=49))
tcp LISTEN 0 4096 127.0.0.1:32843 0.0.0.0:* users:(("casaos-gateway",pid=980,fd=10))
tcp LISTEN 0 4096 127.0.0.1:6060 0.0.0.0:* users:(("crowdsec",pid=1379,fd=48))
tcp LISTEN 0 4096 127.0.0.1:35181 0.0.0.0:* users:(("casaos-gateway",pid=980,fd=7))
tcp LISTEN 0 4096 127.0.0.1:40815 0.0.0.0:* users:(("casaos-user-ser",pid=1148,fd=7))
tcp LISTEN 0 4096 0.0.0.0:111 0.0.0.0:* users:(("rpcbind",pid=499,fd=4),("systemd",pid=1,fd=122))
tcp LISTEN 0 1024 0.0.0.0:80 0.0.0.0:* users:(("lighttpd",pid=9535,fd=4))
tcp LISTEN 0 4096 127.0.0.1:8080 0.0.0.0:* users:(("crowdsec",pid=1379,fd=13))
tcp LISTEN 0 4096 127.0.0.1:39185 0.0.0.0:* users:(("casaos-message-",pid=1055,fd=7))
tcp LISTEN 0 128 0.0.0.0:51413 0.0.0.0:* users:(("transmission-da",pid=9547,fd=15))
tcp LISTEN 0 1000 0.0.0.0:22 0.0.0.0:* users:(("dropbear",pid=705,fd=4))
tcp LISTEN 0 256 127.0.0.1:5335 0.0.0.0:* users:(("unbound",pid=8328,fd=4))
tcp LISTEN 0 4096 0.0.0.0:3000 0.0.0.0:* users:(("docker-proxy",pid=9839,fd=4))
tcp LISTEN 0 5 0.0.0.0:8888 0.0.0.0:* users:(("rpimonitord",pid=9595,fd=5))
tcp LISTEN 0 4096 0.0.0.0:3001 0.0.0.0:* users:(("docker-proxy",pid=9817,fd=4))
tcp LISTEN 0 256 127.0.0.1:8953 0.0.0.0:* users:(("unbound",pid=8328,fd=5))
tcp LISTEN 0 4096 127.0.0.1:32827 0.0.0.0:* users:(("casaos-local-st",pid=1239,fd=9))
tcp LISTEN 0 50 0.0.0.0:445 0.0.0.0:* users:(("smbd",pid=9358,fd=48))
tcp LISTEN 0 511 [::1]:6379 [::]:* users:(("redis-server",pid=9371,fd=8))
tcp LISTEN 0 50 [::]:139 [::]:* users:(("smbd",pid=9358,fd=47))
tcp LISTEN 0 4096 *:33293 *:* users:(("casaos",pid=995,fd=9))
tcp LISTEN 0 4096 [::]:111 [::]:* users:(("rpcbind",pid=499,fd=6),("systemd",pid=1,fd=124))
tcp LISTEN 0 1024 [::]:80 [::]:* users:(("lighttpd",pid=9535,fd=5))
tcp LISTEN 0 4096 *:81 *:* users:(("casaos-gateway",pid=980,fd=8))
tcp LISTEN 0 4096 *:8083 *:* users:(("AdGuardHome",pid=9660,fd=9))
tcp LISTEN 0 4096 *:53 *:* users:(("AdGuardHome",pid=9660,fd=12))
tcp LISTEN 0 128 [::]:51413 [::]:* users:(("transmission-da",pid=9547,fd=16))
tcp LISTEN 0 1000 [::]:22 [::]:* users:(("dropbear",pid=705,fd=5))
tcp LISTEN 0 4096 [::]:3000 [::]:* users:(("docker-proxy",pid=9846,fd=4))
tcp LISTEN 0 4096 [::]:3001 [::]:* users:(("docker-proxy",pid=9823,fd=4))
tcp LISTEN 0 50 [::]:445 [::]:* users:(("smbd",pid=9358,fd=46))
But still not working the dns