It's not your computer; it's IB's servers. They are cheap and slow and highly unreliable. They are down all the time.
Actually, I'd bet it's the software. Why does it take about 15-30 seconds to even load? That's not server. Some people say that it's built on Java and that's why it's slow. But so is ThinkOrSwim (TOS) and TOS is quicker. I bet there's just a lot of bloat built into it as well as poor use of data structures. They could do some simple profiling and figure out where the slow parts of the code are and optimize it, but seems that they are focused on other things. I don't really care though. I don't want to pay for them to come up with something equivalent to TradingView or pay for Bloomberg or CNBC which I don't watch anyway. I just want a reliable, reasonably fast API, and low commissions. If Tradier offered portfolio margin, I'd consider moving there. Hard to find brokers that offer a full API as well as portfolio margin.