These two apps were the main reason why I wanted to solve this problem. I don't have any other apps to up-/download files with. In Google drive, the setting to only transfer files over a WiFi connection is switched off (but it acts as if this setting is switched on), and in Gmail I don't see such a setting. Unfortunately, within apps I still cannot upload/download files. Now, I can finally download and upload files in the Chrome browser (probably also in the other browser, but did not check that). Then, I deleted the APN, and manually setup a new APN, following the steps I found for my device on the website of my provider, including shutting down and restarting the phone First, under APNs I did the reset to default. This is obviously not a solution if you have three different SharePoint sites synchronized with several hundred Gigabytes, along with your personal OneDrive with 10's of GB stored.I followed the steps in the link you suggested. For example, I just created a 637 kb Word document that I uploaded to my OneDrive for Business that I wanted to share with some colleagues over Teams, document is saved and closed on my computer, no one else has it open, but still, the document takes forever (several minutes) to have heard this solution before, but as far as I understand from the 'Disable Files on Demand' feature, all your synched folders are then downloaded to the local harddrive. This has serious implications as it severely impacts the speed at which we can work with and share files. Internet connectivity tests shows good speeds (>50MB/s, all the way up to 300MB/s), but still, OneDrive takes forever to even upload a couple of kilobytes in a Word document. Tested both on and off our VPN client, as well as in numerous Internet configurations (at home, at work), WiFi and cable. We're also experiencing immensely slow upload and download speeds using the OneDrive client, both for Mac and PC, but especially for Mac users.

Google drive upload waiting for wifi