Those messages are the start (cause) of the read errors, that then turn into write errors (on only one disk because Unraid only disables as many disks as there are parity devices.
Jun 9 05:48:00 Tower kernel: sd 1:1:0:3: [sde] Unaligned partial completion (resid=56, sector_sz=512)
Jun 9 05:48:00 Tower kernel: sd 1:1:0:3: [sde] tag#546 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=0x08
Jun 9 05:48:00 Tower kernel: sd 1:1:0:3: [sde] tag#546 Sense Key : 0x3 [current]
Jun 9 05:48:00 Tower kernel: sd 1:1:0:3: [sde] tag#546 ASC=0x11 ASCQ=0x0
Jun 9 05:48:00 Tower kernel: sd 1:1:0:3: [sde] tag#546 CDB: opcode=0x88 88 00 00 00 00 01 06 66 d6 48 00 00 02 f0 00 00
Jun 9 05:48:00 Tower kernel: print_req_error: critical medium error, dev sde, sector 4402370120
Jun 9 05:48:00 Tower kernel: md: disk3 read error, sector=4402370056
Jun 9 05:48:00 Tower kernel: md: disk3 read error, sector=4402370064
Jun 9 05:48:00 Tower kernel: md: disk3 read error, sector=4402370072
Jun 9 05:48:00 Tower kernel: md: disk3 read error, sector=4402370080
Jun 9 05:48:00 Tower kernel: md: disk3 read error, sector=4402370088
Jun 9 05:48:00 Tower kernel: md: disk3 read error, sector=4402370096
Jun 9 05:48:18 Tower kernel: sd 1:1:0:1: [sdc] Unaligned partial completion (resid=16344, sector_sz=512)
Jun 9 05:48:18 Tower kernel: sd 1:1:0:1: [sdc] tag#567 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=0x08
Jun 9 05:48:18 Tower kernel: sd 1:1:0:1: [sdc] tag#567 Sense Key : 0x3 [current]
Jun 9 05:48:18 Tower kernel: sd 1:1:0:1: [sdc] tag#567 ASC=0x11 ASCQ=0x0
Jun 9 05:48:18 Tower kernel: sd 1:1:0:1: [sdc] tag#567 CDB: opcode=0x88 88 00 00 00 00 01 06 6b 24 08 00 00 04 00 00 00
Jun 9 05:48:18 Tower kernel: print_req_error: critical medium error, dev sdc, sector 4402652168
Jun 9 05:48:18 Tower kernel: md: disk1 read error, sector=4402652104
Jun 9 05:48:18 Tower kernel: md: disk1 read error, sector=4402652112
Jun 9 05:48:18 Tower kernel: md: disk1 read error, sector=4402652120
Jun 9 05:48:18 Tower kernel: md: disk1 read error, sector=4402652128
Jun 9 05:48:18 Tower kernel: md: disk1 read error, sector=4402652136
Jun 9 05:48:18 Tower kernel: md: disk1 read error, sector=4402652144