Error-The "Post Meta Information" replacement does not work.

This is a phenomenon that we have confirmed on multiple sites.

Plugin: 2.4.1
WordPress: 5.6.1 (single)
PHP: 7.4.13 1G 300s
Browser: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.150 Safari/537.36
JavaScript: https://one-up-life.com/wp-content/plugins/search-regex/search-regex.js
REST API: https://one-up-life.com/wp-json/
Query: ?page=search-regex.php&searchphrase=%E3%81%AE%E6%A0%BC%E5%AE%89%E4%B8%8D%E7%94%A8%E5%93%81%E5%9B%9E%E5%8F%8E%E3%81%AA%E3%82%89%E5%8F%A3%E3%82%B3%E3%83%9F%E9%AB%98%E8%A9%95%E4%BE%A1%E3%81%AE%E5%BD%93%E5%BA%97%E3%81%B8%EF%BC%81%E5%9C%B0%E5%9F%9F%E3%83%A9%E3%83%B3%E3%82%AD%E3%83%B3%E3%82%B01%E4%BD%8D%E7%8D%B2%E5%BE%97%E5%A4%9A%E6%95%B0%EF%BC%81&source%5B%5D=post-meta

Error: Failed to update meta data: post (searchregex)
Raw: {"code":"searchregex","message":"Failed to update meta data: post","data":null}

johngodley / search-regex

Error-The "Post Meta Information" replacement does not work. #81