Hi, I was also having this problem. I used to submit my urls to the Google Search Console index but all I would get was a "Discovered - Currently Not Indexed" message.
My site has been online for two years and had a very good ranking. I looked everywhere for a solution to my problem, then I discovered this service called IndexMeNow.
Basically, IndexMeNow uses today a combo of 3 indexing methods.
I don't know how it does it, but I was able to solve my problem. I hope I have been helpful.
