Holy shit.
This is bad. You really can't run Photoshop without 32GB of RAM these days.
This is cata-bloody-strophic. You have to get that figure up to at least 150GB, pronto.
Yes, that might work too.
Yes, the background.
It would be best if you had a photo with the massive sun flare on their heads too; or else find a different example photo without it.
That's probably because there is no edit data in the xmp files.
It sounds like you didn't have this turned on in LR? Three reasons to enable XMP files in Lightroom Classic - Photofocus