Jul 5 09:39:17 Tower kernel: ahci 0000:03:00.0: AHCI controller unavailable!
Problems with the Marvell controller, and all devices connected there dropped, Marvell controllers are not recommended for Unraid, first thing I would recommend is replacing it with a recommended controller, once that's done (or if you don't want to do that for now just power cycle the server) run a scrub on the pool and post new diags.