Your certificate has been logged by all kind of logs. The logs which are running yearly shards all list the 2021 shard.
I had asked something about this earlier and if I recall it correctly, the notAfter date determines the shard you'll have to choose. In this case 2021. (Source: How is it possible ? future logging)
Unfortunately, I don't know how the Comodo logs are temporally sharded.
In a Let's Encrypt blogpost there are 2 links in the Sharding section: https://letsencrypt.org/2019/11/20/how-le-runs-ct-logs.html