Ngb-bootstrap alert close button style is not apply properly

I’m working on an Angular project that uses the ngb-alert to show alerts. My alert is working fine, but when I upgrade my Angular version and all other dependencies to the latest, I notice that the close button of the alert is jacked up.

<ngb-alert [type]="'success'" (closed)="onAlertClosed();">
    Text of alert
</ngb-alert>

Here is what I am using

angular- 18.2.8

ngboostrap – 13.1.1
Bootstrap – 4.5.3

I already checked with style overlapping and missing dependencies.