Why is the Kendo UI (AngularJS) affected by an NGX update?

I work on an enterprise application that has a mix of AngularJS (v1) and NGX (v2+) pages. We employ Kendo UI to construct Grids for list pages in the app.

Recently, we updated the the NGX portion of our application to Angular 12 via these update steps. After doing so however, the “items per page” text that usually appears at the bottom of the Kendo Grid next to the page size drop down disappeared from grids that are on AngularJS pages.

I’ve tried reverting the i18n migration step in the Angular upgrade guide which changes message IDs (“items per page” is one of the messages in messages.xlf) but this didn’t help.

I also tried modifying the $scope‘s gridOptions that set the messages on the grid based on these docs i.e.

pageable: {
   .
   .
   .
   messages: {
      itemsPerPage: "items per page"
   }
}

but this also didn’t work.

What’s interesting is that if I modify the display or empty properties in messages, I do actually end up seeing a change. It’s itemsPerPage (among other properties) whose updates can’t be seen on the front-end. This might be a symptom of the same issue.

Anyone have ideas as to why this might be happening? Are there any incompatibility issues with certain versions of @progress/kendo-angular-<package_name> with version 12 of Angular?