Do you have a stable internet connection? What is your internet speed?
This is what I found
2021-12-21 11:30:58 WARN_NET_LOST: network connection lost
2021-12-21 11:30:58 will power off in 72 seconds in case not resume
2021-12-21 11:32:09 network connection lost for 5 min + 72 seconds, power off...
2021-12-21 11:32:16 chain avg vol drop to 1.27
2021-12-21 11:36:04 ****power off hashboard****
Can you try to run or switch to another pool server if you are living on ASIA you should use an ASIA pool server or if you are living in the US then you should use a US pool server to get the lower latency?
Also, notice this
021-12-21 11:36:09 Invalid config option --bitmain-fan-pwm: '' is not a number
2021-12-21 11:36:09 Invalid config option --bitmain-freq: '' is not a number
2021-12-21 11:36:09 Invalid config option --bitmain-voltage: '' is not a number
2021-12-21 11:36:09 Invalid config option --bitmain-ccdelay: '' is not a number
2021-12-21 11:36:09 Invalid config option --bitmain-pwth: '' is not a number
2021-12-21 11:36:09 Invalid config option --bitmain-freq-level: '' is not a number
and this below sometimes it doesn't have a fan power signal
2021-12-21 11:24:05 fan_eft : 0 fan_pwm : 0
The fan might be the issue that is why you have an invalid config option according to the above logs.
Try to upgrade it to the latest version and test it again if your issue doesn't solve then post the whole kernel logs again here.