Through my extensive experimentation, I discovered that utilizing .includes() in the .html template can cause issues with the application when running on Internet Explorer.
For example,
*ngIf="selectedItems.includes(item)Despite enabling all necessary settings in polyfills.ts, Internet Explorer still struggles to interpret my code correctly. Interestingly, elements like {{aVariable}} will not render in IE if they include an includes() statement. However, adding a *ngIf="true" directive within the HTML tag seems to resolve this issue:
<span *ngIf="true">{{aVariable}}</span>Once I removed all instances of .includes() from the .html template, the application ran smoothly once again. The question remains - is there a solution for this problem within the polyfills configuration?