Hello JulialoLo, my name is Irisdiel and I am an independent advisor.
Here are a couple fixes you can try that may fix your issue:
-Disable/enable Enhanced Protection Mode.
-Try all possible proxy settings.
-Reset IE 11.
-Remove IE 11 from Windows features and re-installed it.
-Disable all add-ins.
-F12 developer tools change the browser profile and user agent string.
-Compatibility View settings, all possible setting combinations.
-Change the DNS servers on the network adapter from default to specify various free DNS providers (updated)
-Attempt Fiddler analysis, getting to trace from sites where the problem occurs (updated)