Cloudflare Ethereum Gateway Returns 'Worker threw exception'

Hello, the Ethereum Gateway offered by Cloudflare appears to have critical issues.

When I use the eth_getBlockByNumber method, any block that has not been recently mined returns an HTML page with the title Worker threw exception | cloudflare-eth.com | Cloudflare.

I am testing this using the official example in the documentation - Interacting with Ethereum · Cloudflare Distributed Web Gateway docs.

curl https://cloudflare-eth.com -H 'Content-Type: application/json' --data '{"jsonrpc":"2.0","method":"eth_getBlockByNumber","params":["0x1b4", true],"id":1}'

For comparison, when I change the value to get a block that was recently mined, the correct response is returned. If I attempt to query this block later though (after a few hours), it will start returning ‘Worker threw exception’.

Apologies if I chose the incorrect category, I wasn’t sure which would best suit this post.