Abdelrahman Abdelrazek there are some limitations when working with IE11. Note that even Microsoft recommends using Microsoft Edge (instead of IE11).
A few things to try:
1) Version 4.10 just released, so I would try updating to that version and see if there is a change in behavior.
2) Are there any warnings or errors in the console? Apart from the FeatureLayer being too heavy to load in IE11, there could be other issues here, such as methods or properties that are not supported in IE11.
3) Have you tried with other versions of IE11? There are actually different versions of IE11, depending on the OS and if the browser is automatically updated or not.
4) Lastly, we list the recommended browsers in our documentation, so if there is a need to justify using a different browser, we have that covered.
ArcGIS API for JavaScript 4.10 - Supported Browsers
System Requirements | ArcGIS API for JavaScript 4.10
Hope this helps.
-Noah