bug(MATSELECT): mat-select (drop down) lags on large data set for iPad

[smil-thakur]

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

18

Description

when the length of list increase to more than 20 the drop down scroll lags on iPad

Reproduction

Steps to reproduce:

1. create a simple mat-select with mat-options
2. attach an dummy array of length > 50 to the mat-option using @for or *ngFor
3. scroll and observe

dropdown.load.test.mp4

Expected Behavior

it should scroll smoothly without lag

Actual Behavior

scrolling stuck and lags for fraction of seconds

Environment

• Angular: 19
• CDK/Material: 19
• Browser(s): safari/chrome for iPad
• Operating System: iPadOS 18.3