p-select: with virtual scroll and filter, option list gets hidden after clearing clearing letter one by one

[volopankiv]

Describe the bug

We are using p-select with virtual scroll and filtering enabled. When we enter a query that has no matches, the component displays the “No data” placeholder. After removing characters one by one until results appear again, the overlay height becomes too small to display even a single option.

Pull Request Link

No response

Reason for not contributing a PR

• Lack of time
• Unsure how to implement the fix/feature
• Difficulty understanding the codebase
• Other

Other Reason

No response

Reproducer

https://stackblitz.com/edit/3sjehehg?file=src%2Fapp%2Fselect-lazyvirtualscroll-demo.ts

Environment

All environments.

Angular version

20.3.15

PrimeNG version

v20

Node version

22.18.0

Browser(s)

145.0.7632.117 (Official Build) (64-bit)

Steps to reproduce the behavior

1. Start typing input in the select filter with virtual scroll support untill you get no results. (In reproducer enter 0000)
2. Remove each input character one by one until you get some results. (In reproducer remove one zero)
3. The list with options is not visible

Expected behavior

Should show a complete list of matched options (with scroll in case we have more than fit in our overlay popup)

[github-actions]

Thanks for opening this issue!

To help us investigate, could you please provide:

• Confirmation that issue still reproduces in latest PrimeNG version
• Whether virtual scroll specific behavior or applies to non-virtual scroll as well
• Browser console errors or warnings during reproduction

Without these details, we may not be able to investigate this issue.

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[MatiasGrimm]

Also encountering this issue for Angular@21.1 & PrimeNG@21.1
Looks like it's only when using virtual-scroll.
While looking at the rendered code, it looks like height of scroller element isn't recalculated based on "visible options".