Could you add an option that would pause all FDM downloads if internet activity is detected, and then resume all previously paused downloads when no internet activity is detected?

It's some kind of misunderstanding, I'm afraid. FDM is a user level app, not a system tool. Your suggestion (network traffic prioritizing) is a job for network tools like firewall or internet security suite.

49studebaker wrote:Could you add an option that would pause all FDM downloads if internet activity is detected, and then resume all previously paused downloads when no internet activity is detected?

This is a rather unusual suggestion. Do you mean that there should be an option to run FDM only as a background app when no other online processes are running?

My internet connection speed is 64k. If I web browse while FDM is downloading a file, web pages take longer to load. I have to manually pause the FDM download and then load the webpage I want to view. After the webpage has finished loading, I have to manually resume the FDM download.

Hi, this is a recent optimization issue, we're working on it.

49studebaker wrote:After the webpage has finished loading, I have to manually resume the FDM download.

So you want to restore "Decrease traffic usage on browser activity" option available in FDM 3.x rather than run FDM as a service. FDM 5.x automatic settings prefer more aggressive network usage than settings in FDM 3.x, so this option should be really useful.
Note that in need you should better use light mode (with proper settings) than pause downloads – many servers may break extremely slow connection and close session so you may be forced to restart download from the very beginning.