Hi all. Mozilla Firefox is very slow on my Linux Laptop with the Qualcomm Atheros QCA9565/AR9565 Wireless Network Adapter (with open-source driver ath9k). It takes a lot of time to resolve hosts and to load the webpages. I am reporting the issue here because Chromium and the rest of web explorers work good and they are as fast as one may expect. When using Windows 10 with the same laptop, Firefox also has no issues and works perfectly well. It appears to be an issue of the combination of Firefox + this specific driver & network adapter. Used Manjaro, Ubuntu 16, Ubuntu 20 with a lot of kernels ranging from 4.15 to 5.8 and the issue persists and does not seem to be tied to any specific distribution. I can do some tests if you require so.