I installed the software (2.9.0.60) about two weeks ago on my iMac (11.4). Since then, my mac has gotten very slow browsing the internet. The problem is most noticeable when going to a new websites. But it also effects other apps, like spotify, that are net dependent. All non-net dependent activity is fine. I was looking for a troubleshooting guide for this, but did not find one. I have rebooted several times, no effect. What next?