For a while now, several bank credit card sites are not working correctly when I use my Firefox browser. It did in the past and I didn't have any problems but lately I'm having these problems happening on sites I've used for years. If I use another browser it will work with no problem. In fact after talking with some of the support people at some of the sites that won't work, the suggest trying another browser which works fine. I'm talking like American Express' website which I use a lot. There are other sites other than credit cards that are not working correctly and again, their support agent will tell me to use another browser. I have tried different remedies like clearing cache, history, etc. I only use few addons like AdBlock which helps to cut down on trackers and information gathers. I have set my preferences to clear out my history and cookies. I have used Firefox for so many years without problems and with the same addons without any problems. So what is causing this to happen? I do enjoy using Firefox but if I have to keep changing over to another browser so sites will work, then maybe it's time for me to stop using Firefox.