I don't know this is a Lubuntu problem or a Chrome one so I post here first before heading to the Chrome bug tracker.
Previously, when I save something in Chrome, this dialog box is used:
Today, after updating to Chrome 93, this box pops up:
How can I fix that?
Update: default file manager is still PCManFM-Qt.
Update 2: This Github diff contains the commit that cause the change. Version 93.0.4566.0 is the first to exhibit this behavior. Here's the changelog between it and its previous build.