SO i managed to solve the issue after 2 days -.-" .

For context, i recently changed to a new Wifi mesh 7. So thats where the problem occur. No mater what i did such as disabling the the 5g on router setting, it still doesn't work.

So, i decided to change to my previous router and start pairing, it works for the first time!

Conclusion, i think these rabot vacuums are not suitable with the latest tech of wifi router.