Starting from last Wednesday/Thursday, due to a few days of heavy rain(I am guessing), we are experiencing about 10% packet loss.
Here is the graph 10% PL 9/24: https://share.pingplotter.com/hzTswF3XScG#

So we called the ISP, and the technician came in on Monday, 9/25, and tested the coax cable and saw the issue was with the coax cable. He told us part of the coax cable was outside of our townhouse, and he said the issue could be the connector or the coax cable exposed to the sunlight and the rain, so he switched them for us and made sure it was protected to prevent further wear. Then he tested with his device and saw no problem with the cable and the modem and then he left. The problem is almost gone and the PL was at 1-2%.

But today the problem came back, I am guessing due to the weather again. It even caused a flood warning, and the packet loss rose up to about 5-8%.
Here are a few graphs in the past few days:
9/27 https://share.pingplotter.com/dhcCaaCXmMv
9/29 https://share.pingplotter.com/Db51934qYLr
9/29 https://share.pingplotter.com/dzhLHF6QaYn

I contacted the ISP again just now, but they don't see any signal problem on their end, and they are sending a new tech to come in tmr to switch the modem. However, the last tech already switched the modem for us with a new one, so I don't think it is a modem problem.

How can I go from this? Is it really caused by weather? Does switching modem really help? Before last Wednesday, we didn't have any problems (less than 1%PL I guess because I usually play competitive games in the morning and it was super smooth) even if it was raining heavily. The PL happened very randomly, as I am typing here, it went to 1.8%.
One thing I noticed is that for the 2nd hop, the IP from pingplotter shown for ISP modem is 158.222.160.1, which is different from what is shown in the settings of my asus wifi router, WAN IP:158.222.183.228. Could it be one of the reasons?

Hi noobita220!

Thanks for providing those share pages! That makes it really easy to help you.

The poor weather could be contributing to the packet loss you're experiencing. It's hard to know exactly what is causing the problem with just PingPlotter though.

What we do know for sure, and what you've already found out, is that the packet loss is being first introduced in the route at hop 2. This is a good indicator that the issue is with the route between your router and your ISP's border router, or with the device at hop 2 itself.

I would recommend sending this same PingPlotter data to your ISP (if you haven't already) as evidence of the issues you're experiencing. Here's a good guide you can follow to help build your case: https://www.pingplotter.com/fix-your-network/outside-network-problems/

As for seeing different IP's is your Asus Wifi router is probably reporting it's own public IP address. I suspect if you went to a website like https://whatismyipaddress.com/ you would see 158.222.183.228 (or something similar, these tend to change frequently). The 158.222.160.1 is most likely the public IP of your ISP's border router.

I hope this info helps! Good luck to you!