I also have this issue and my internet is 100mbit and no other download going on in the background.
I've already tried doing the instructions here: https://answers.ea.com/t5/Bug-Reports-Technical-Issues/Address-game-download-install-issues/m-p/9862645/thread-id/839 which i think made the issue worse! I've submitted a error report using the option from the EA desktop menu.
Just an update.
I tried the solution above about a clean boot, but that did not fix the issue.
However it appears to be working again. It might be one of a couple of things. When re-enabling some startup programs, i never enabled some razor programs such as Synapse 3, Cortex launcher, gameglass launcher and also updated the nvidia drivers to the latest 471.11. The app then crashed twice and gave me the option to recover. Something changed to put my downloads back to full speed.
