Try custom firmware, custom means non-bitmain, try Asic.to or BraiinOS see if the miner behaves any differently, although since you upgraded to the latest version this won't be easy, not sure if the Sdcard method will work anymore.
2020-11-06 12:18:09 driver-btm-api.c:1042:check_asic_number_with_power_on: Chain[0]: find 27 asic, times 0
2020-11-06 12:18:41 driver-btm-api.c:1042:check_asic_number_with_power_on: Chain[1]: find 18 asic, times 0
2020-11-06 12:19:32 driver-btm-api.c:1042:check_asic_number_with_power_on: Chain[2]: find 0 asic, times 2
under normal circumstances, I would say all 3 boards are dead because they don't see 30 Asics which is the normal asic count for T17, but since this only happened after the firmware upgrade (if I understood you correctly) then I would think that the firmware is causing the issue.