TypeError: Window.getComputedStyle: Argument 1 is not an object.

[Harwinderkheri]

When keen slider (for angular project) is initialize in firefox (version 119) in iframe, below error occurs:
TypeError: Window.getComputedStyle: Argument 1 is not an object.
m keen-slider.es.js:1
b keen-slider.es.js:1
y keen-slider.es.js:1
k keen-slider.es.js:1
y keen-slider.es.js:1
y keen-slider.es.js:1
y keen-slider.es.js:1
ngAfterViewInit Slider.component.ts:51
Angular 21
ngAfterViewInit Slider.component.ts:49
Angular 63
RxJS 6
Angular 20
ngAfterViewInit MobileView.component.ts:26
Angular 9
keen-slider.es.js:1:14381

Initialize:
this.slider = new KeenSlider(this.sliderRef.nativeElement, {});