1.Does anyone else have the same problem in your organization? Yes, it was reported by several users and I was able to recreate that I had the same problem
2.Did you do any operations before this issue occurred? No, I was working on migrating those flows into a solution, but this was reported to have started about two weeks ago, before I touched the flows
I found the official documentation for creating an approval flow that requires everyone's approval, and you can follow the steps to test if the issue persists.
https://learn.microsoft.com/en-us/power-automate/all-assigned-must-approve
Also, to narrow it down further, try using Approvals in the Teams client to see if the issue exists.
--The problem is in the Teams client.