Hi!
On Google Search Console in the " Page indexing" (Index → Pages) page if you scroll down you should see the reason why your pages are not indexed.
It should look something like this:
A more detail informations about each reason can be found here: Index Coverage report - Search Console Help
In the “Source” column you have the source of the reason (can be “caused” by the website or by Google).
Keep in mind that for the “Crawled currently not indexed” reason, Google clearly states the following:
“The page was crawled by Google, but not indexed. It may or may not be indexed in the future; no need to resubmit this URL for crawling.”
In other words Google might not decide to index your page, and from my experience pages with low content usually don’t get indexed.
Hope this helps!