Entire Unifi network is down, after public ipv4 gateway out to the internet is broken, not your house issue.

Target Name: one.one.one.one
        IP: 1.1.1.1
  Date/Time: 9/28/2025 9:28:57 PM - 9/28/2025 9:38:57 PM

Hop  Sent  PL%    Min    Max    Avg  Host Name / [IP]
  1    51    0  0.39  0.65  0.50  192.168.88.1 [192.168.88.1]
  2    52    0  1.37  5.42  3.22  218.111.255.254 [218.111.255.254]
  3    48  54  8.14  71.38  12.61  10.55.51.35 [10.55.51.35]
  4    52  12  4.56  32.73  8.36  10.55.52.31 [10.55.52.31]
  5    52  21  10.14  20.77  15.43  10.55.37.84 [10.55.37.84]
  6    49  14  6.09  67.31  15.45  162.158.24.253 [162.158.24.253]
  7    49  16  7.90  19.52  15.32  one.one.one.one [1.1.1.1]

i just do a test on your ip subnet gateway 218.111.255.254, its seem unusual high possible ddos attacked.

and i try another subnet 218.111.239.254 doesn't have this issue.

i though  i was the only one having the problem just now, 20mbps down 550 mbps upload on 1Gbps , it was from 8pm~1210am today

Fast.com was 20mbps

Ya, its not normal, how about try to a reset on onu and router get a new ip and do a test again?