File permissions being reset after using appimagetool

I am currently building a .NET6.0 application and then moving the files to my AppDir/usr/bin folder.
After moving the files, i run chmod on the target file to set the permissions and make it executable, but after running the appimagetool to generate my appimage, the AppRun file complains about permission denied when it tries to run the target executable.

I ran a ls -l on the file prior to packaging it, and after, using –appimage-extract to access the files and the permission does indeed change from -rwxr-xr-x to -rw-r–r–

Might be worth noting that this runs in a build pipeline. A weekish ago when i were learning about app images, i did manage to build and run the appimage manually on the same machine. This issue now occurs during the pipeline which runs on a different machine, but i still download the appimage and try to run it on the same machine that i used last week.

Update
I got it working. From C# i were running a bash process to chmod the file, but by adding the chmod command to a bash script on the machine that is generating the appimage, and then running said bash script through C#, it suddenly worked.