I did another check. At the time that this alarm is triggered:
01/05/2021, 8:49:39 PM Hardware Sensor Status: Processor green, Memory green, Fan green, Voltage green, Temperature green, Power green, System Board green, Battery green, Storage green, Other red
I checked the syslog on ESXi host in a time duration from 8 PM to 9 PM. I guess the object is BMC which is not critical as I think.
2021-01-05T20:30:00Z crond[2098816]: USER root pid 2269536 cmd /bin/hostd-probe.sh ++group=host/vim/vmvisor/hostd-probe/stats/sh
2021-01-05T20:31:37Z sensord[2269535]: ipmi_completion: expected at least one byte/completion code to be returned, retries left: 10
2021-01-05T20:31:57Z sensord[2269535]: recv_reply: bmc timeout after 20000 millisconds
2021-01-05T20:31:57Z sensord[2269535]: ipmi_completion: no reply, failed to communicate with bmc
2021-01-05T20:35:00Z crond[2098816]: USER root pid 2269550 cmd /bin/hostd-probe.sh ++group=host/vim/vmvisor/hostd-probe/stats/sh
2021-01-05T20:40:00Z crond[2098816]: USER root pid 2269564 cmd /bin/hostd-probe.sh ++group=host/vim/vmvisor/hostd-probe/stats/sh
2021-01-05T20:45:00Z crond[2098816]: USER root pid 2269578 cmd /bin/hostd-probe.sh ++group=host/vim/vmvisor/hostd-probe/stats/sh
2021-01-05T20:50:00Z crond[2098816]: USER root pid 2269592 cmd /bin/hostd-probe.sh ++group=host/vim/vmvisor/hostd-probe/stats/sh
2021-01-05T20:51:29Z sensord[2269535]: ipmi_completion: expected at least one byte/completion code to be returned, retries left: 10
2021-01-05T20:51:49Z sensord[2269535]: recv_reply: bmc timeout after 20000 millisconds
2021-01-05T20:51:49Z sensord[2269535]: ipmi_completion: no reply, failed to communicate with bmc
2021-01-05T20:51:49Z sensord[2269535]: Warning: Unexpected error Failure
2021-01-05T20:51:49Z watchdog-sensord: '/usr/lib/vmware/bin/sensord -l' exited after 1317 seconds 1
2021-01-05T20:51:49Z watchdog-sensord: Executing '/usr/lib/vmware/bin/sensord -l'
2021-01-05T20:51:49Z sensord[2269609]: ipmi_completion: IPMI completion code for msgid: 5, cc = 0x80
2021-01-05T20:55:00Z crond[2098816]: USER root pid 2269613 cmd /bin/hostd-probe.sh ++group=host/vim/vmvisor/hostd-probe/stats/sh
2021-01-05T20:59:40Z sensord[2269609]: ipmi_completion: expected at least one byte/completion code to be returned, retries left: 10
2021-01-05T21:00:00Z sensord[2269609]: recv_reply: bmc timeout after 20000 millisconds
2021-01-05T21:00:00Z sensord[2269609]: ipmi_completion: no reply, failed to communicate with bmc