Hummingbird not clearing cache unless I deactivate and reactivate plugin

Hi, I can't see any css or js changes without deactivating and then activating the hummingbird plugin. Do you know why this would be happening? I have tried clearing my cache. Maybe it is a setting that I don't know about, but I use hummingbird on multiple sites and don't have this problem and all the settings are the same, so I am stumped. Thanks in advance!