Can’t open microsoft office files directly in File App in iOS and iPadOS

I have a problem. I cannot open microsoft office files directly from File app both in my iphone pro 16 and my ipad pro m4. The files are only able to open if it is open in Microsoft App ie. Words and OneDrive. It was fine before OS 18. I’m guessing it’s apple File app’s or apple mobile OS problem because it works fine on my mac Finder app. And recent microsoft app update does not solve this problem.