Difficulty history not working

[jsarenik]

Describe the bug

At https://bitcoinexplorer.org/difficulty-history the "Loading data" does not finish. Keeps hanging. For some months at least.

Environment (please complete the following information):

• whatever runs bitcoinexplorer.org

Configuration file content

Please include the content from the following files. BE SURE TO MODIFY YOUR CREDENTIALS BEFORE SUBMITTING!!!

• bitcoin.conf
• Your btc-rpc-explorer environment configuration (either $WORKING_DIR/.env or ~/.config/btc-rpc-explorer.env)

To Reproduce

Steps to reproduce the behavior:

1. Go to 'https://bitcoinexplorer.org/difficulty-history'
2. See "Loading data" which never finishes.

Screenshots or Log Output

Additional context

It works at https://be.anyone.eu.org/difficulty-history but note it is generated by a script into static JSON files on eachepoch change. Uses the same concept as the last btc-rpc-explore version it worked on but generates the one HTML and JSON data files statically only once (on a new epoch).