I have updated from Angular 8.x to Angular to 9.x and the Syncfusion schedule package to 17.4.55.
I can confirm that after the update the following ng-template templates in the scheduler are not working anymore:
#eventSettingsTemplate
#timeScaleMajorSlotTemplate
#quickInfoTemplatesHeader
#quickInfoTemplatesContent
These ones are still working as before the update:
#cellTemplate
#resourceHeaderTemplate
To give you at least one example of the issue:
It looks like all the timeScale templates are not working anymore.
Is this a known issue/work in progress?