504 Gateway even when the IPFS node is up and running

Hey. So we have an IPFS node, backed by S3 bucket. It works well, we have uploaded some files some time ago, so no new files, we just use those that were uploaded earlier. But anyway from time to time we see 504 gateway errors (we use https://ipfs.io/ipns/k51…). Is this a gateway issue? Or is this might be related to the issue with our IPFS node?
Will it be beneficial to create several IPFS nodes in different data centers with the same data?

On my node, I see a lot of other nodes with ipfs swarm peers, so the node is connected to the network.