It appears that the setup in question was only working through coincidence in previous versions. I added the developer comment as a public note on the ticket, but it appears that currently this is a desired feature that will be considered for implementation in the future.
The best fix I can suggest here is for the user to copy the depth texture and use that during the UI rendering. This is a desired feature but there isn’t a stable path to support it right now but that will be looked into for future engine versions.