Yes, I also have those issues. I'm having the same problems every day. Charts don't seem to load or reload when changing time frames around the US market opens. Also, when I trade they do not always show up in my trades column. Very frustrating, indeed!
Why are charts not loading sometimes? It seems to happen when trading volume is high, like when the US market opens. It happens at crucial times, and often enough that I am starting to look at other providers. It seems to make no difference which browser I am using.