Ion-select multiple crash on device + ngFor + data

hi , i have a little trouble with ion-select multipe with real data, in simulator i dont have any problem data is displayed , and all works , but when i try this on device , the app just freeze by not opening the ion-select, i have an another ion-select in the form , but not multiple this time , and its works perfectly even with devices.

<ion-select [(ngModel)]="skills" multiple="true" cancelText="Fermer" okText="Ok"> <ion-option *ngFor="#sk of skillPlain" checked="false">{{sk.text}}</ion-option> </ion-select>

skillplain its a json with a lot of skills inside (62).