Type not altered after property_exists on object literal

[M393]

https://psalm.dev/r/55a6758cbd

I'd expect the property to be a string inside the if, but still getting warning about possible undefined property.

Maybe related: #4182, #8196

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/55a6758cbd

<?php
/** 
 * @param object{s?: string} $p
 */ 
function f(object $p): void {
    if (property_exists($p, 's')) {
        /** @psalm-trace $p */
    }
}

Psalm output (using commit 0221ff1):

INFO: Trace - 7:0 - $p: object{s?:string}