New images not accessible in frontend/backend

Hi, since our upgrade to the latest version last week (5.2.24), we found out that any new image upload can not be displayed in either frontend / backend. After further check, we found out that the file and folder to these images are created with wrong permission (700 for folder / 600 for files). After updating it manually (to 750/640), they work perfectly fine again. However, the problem persist for every new upload and we have to repeatedly update the permission again manually.

Does anyone have any hints about what the problem could be or any tips of what needs to be checked?

We have finally solved it. After many research and test, we finally solve the problem simply by clearing all cache. Never though that this could have such effect, should have tested it first.