I assume you've already tried restarting PS5 and retrying upload? The engine request failed error sounds like the payload running on the PS5 itself is erroring out, so clearing cache and retrying may fix it.
Is the PS5 and PC wired or wireless...
just use ftp or usb transfer.. alot of these "mangers" and "uploaders" are still early stage and probably contain bugs and b) alot of vibe coding nonsens popping up as well.. just use the good old ftp if u just do remote uploading or copy to usb...