Plugin store mongo_replset: got unrecoverable error in primary and no secondary error_class=Encoding::UndefinedConversionError error="\"\\xC3\" from ASCII-8BIT to UTF-8"

My config td-agent
```

@type mongo_replset

time_key updated_at

nodes 1.2.3.4:27017,1.2.3.5:27017,1.2.3.6:27017
replica_set abc
database abc
collection logs_%m_%Y
user ...
password ....
date_keys created_at,request_time

@type file
path /var/log/td-agent/buffer/mongodb
timekey 60
timekey_wait 60

```
Some log code have special-character word like `{"character": "༂Sυɠαɾ ɗαɗү࿐"}`. This log can't push to mongo and I was checked file log td-agent.log:
```
2020-09-18 09:58:02 +0700 [warn]: #0 got unrecoverable error in primary and no secondary error_class=Encoding::UndefinedConversionError error="\"\\xE1\" from ASCII-8BIT to UTF-8"
2020-09-18 09:58:02 +0700 [warn]: #0 suppressed same stacktrace
2020-09-18 09:58:02 +0700 [warn]: #0 bad chunk is moved to /tmp/fluent/backup/worker0/object_3fba0e62a1a8/5af8da4b100f9f43f77fac346c1c4274.log
```
I'm using
OS: Centos 7
td-agent 3
Can everyone help me?