I managed to solve it.
I don't know why it happened, but the fix was like this.
Started a ping from the router itself to the default gateway (the ISP) and disabled all the ip's except the one working.
Then disabled the one working and enabled the next one. After doing this the 2nd ip started to work. Then disabled 2nd and enabled third and so on till the last one. Basically disabled the working one and enabled a non responsive one while keeping the ping working.
One by one started to reply from the outside like this. I have no idea why this happened, if it was something related to the router or to the ISP router (maybe kept the old mac address old arp table not sure).
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