this behavior can be caused by a MacOS bug with the sandbox security system. If this is the case you can try to reboot your mac, but some users had more luck using the small + at the bottom left of Pixa's interface to add Live Folders.
on 20 May, 2018 08:17 AM
Things works, now, it’s a pity that doesn’t work with Affinity designer or photo files. Affinity lacks of its own “Bridge”, i read that you said that was hard to keep this software going on, maybe they could be interested ;)
Sorry not my business but a thought.