CPU utilization is greater than 80, on the specific VM

We are getting this alert since yesterday on the specific VM
CPU utilization is greater than 80.
Which gets resolved automatically. But need to check why the alert has started to come now.

Also when I checked overall CPU utilisation for the specific vm in monitoring tool ,
found Overall CPU utilisation for all cores is average 5%-6% . One of the cores might have high utilisation at that point.

mongod log sample entry:

{“t”:{"$date":“2022-04-06T06:22:11.337+00:00”},“s”:“I”, “c”:“ACCESS”, “id”:20436, “ctx”:“conn4812791”,“msg”:“Checking authorization failed”,“attr”:{“error”:{“code”:13,“codeName”:“Unauthorized”,“errmsg”:“not authorized on admin to execute command { find: “system.version”, filter: { _id: “shardIdentity” }, limit: 1, singleBatch: true, lsid: { id: UUID(“476e968c-d8db-41f0-bf0e-9a5a58dc1da7”) }, $clusterTime: { clusterTime: Timestamp(1649226413, 666), signature: { hash: BinData(0, D4123AA36EB1598F8EF4376EB8CEDDBE20F85764), keyId: 7029869742718451713 } }, $db: “admin”, $readPreference: { mode: “primaryPreferred” } }”}}}

ps -ef | grep [m]ongo
mongodb 11256 1 71 2021 ? 120-00:23:55 /usr/local/bin/mongod --config /apps/mongodb/config/mongod.conf --fork
root 23433 39601 11 Mar30 ? 17:27:46 /usr/local/percona/pmm2/exporters/mongodb_exporter --collector.collstats-limit=200 --collector.diagnosticdata --collector.replicasetstatus --compatible-mode --discovering-mode --mongodb.global-conn-pool --web.listen-address=:42002
root 63831 2602 0 06:21 ? 00:00:00 sshd: mongodb [priv]
mongodb 63850 1 0 06:21 ? 00:00:00 /lib/systemd/systemd --user
mongodb 63851 63850 0 06:21 ? 00:00:00 (sd-pam)
mongodb 63989 63831 0 06:21 ? 00:00:00 sshd: mongodb@pts/1
mongodb 63992 63989 0 06:21 pts/1 00:00:00 -bash