Shared buffer hash table corrupted

Running 9.6.15, this morning we got a 'shared buffer hash table corrupted' error on a query. I reran the query a couple hours later, and it completed without error. This is running in production on a Linode instance which hasn't seen any config changes in months.

I didn't find much on-line about this. How concerned should I be? Would you move the instance to a different physical host?

Thanks,

Mark