Hi Hossam Z, I hope you are good.
There can be many reasons that can be causing this issue, the most commons are:
1. You are not seeing the same Document Library when selecting. To confirm this is the case, copy the URL of the library and give it to another colleague to know if that person is seeing the same.
2. The folder can have access restrictions. Try creating a new folder and share that with another colleague to know if he can see the changes.
Some companies have a check-in and check-out feature so if you create a new document and uploads it but does not check it in, the others cannot see it.
Make sure this is not the case. Here more info that can help troubleshooting:
Add the Documents tab to the main form for a table - Power Apps | Microsoft Docs
If this answers your question, please chet it as verified to help other find useful information.
Welcome to this amazing community.
