bug(table/button): Z-index and scroll issues in a sticky table

[FiReBlUe45]

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

14

Description

I have two bugs with a sticky mat-table and not with table with mat-table directive :

• The button's z-index has changed since version 15.0.0. The sticky and button column are both 1, which makes the button visible (but not the table background), a Workaround st z-index to 2 on sticky column.
• When I have several columns in a table with a fixed column, the fixed column also moves.

Reproduction

StackBlitz link: https://stackblitz.com/edit/tu9ax3

Expected Behavior

That anything that scrolls under the sticky column is not visible and the sticky column is real sticky.

Actual Behavior

The button is above the sticky column, and the sticky column is not really sticky.

Environment

• Angular: 15 - 16
• CDK/Material: 15 - 16
• Browser(s): Chrome Lastest version
• Operating System (e.g. Windows, macOS, Ubuntu): Windows 11

[stuhops]

Just came here to report this. I have the same thing with mat-flat-button where the z-index is 1 for the text. Obviously I can adjust my other styles, but I don't feel like I should have to dive this far to update to mdc compatible theme