Same Problem. My version is 12.1.7061.6600. Here is the first log message:
/Users/charlesdill/Library/Caches/com.apple.Safari/WebKitCache/Version 12/Records/0C040C1
Miner.Jswebcoin
Here is the second log message:
/Users/charlesdill/Library/Caches/com.apple.Safari/WebKitCache/Version 12/Records/0C040C1
Miner.Wasmwebcoin