A pluralization once popular in 14th Century Middle English that died out until ressurected in central north American business English.
In 2016 Grammarist was to the point.
"Learnings is a pluralization of an erroneous form of learning as a singular noun. Said singular noun (e.g., a learning) does not exist, at least according to most dictionaries. Colloquially, especially in the medical field, learnings means specific items that were newly discovered or learned."
In 2016 Grammarist was to the point.
https://www.quora.com/What-is-the-plural-form-of-learning-Is...they're since softened that stance and now discuss how it is poorly used.
https://grammarist.com/usage/learnings/