Some of my coins are from 2014, I ran the fix / repair wallet stuff on the wallet and they came out fine.
I got 21 coins of interest on 1/10/2018.
I also bought some coins on 1/24/2018, so that makes them a bit over 14 days.

My Stake value on Overview says : 0
the console info shows my coins weight is 2935 and network weight is 2442167.
I have a 50% chance of interest in next 19 days.  (per getinfo/getmininginfo)

I hope that helps with any suggestions as to what to look for.   I do try to keep the wallet fired up most of the week to help out.
I'd hoped to see even a little number show up in Staked! 

Thanks for the tip on having more than 1000 coins too.  I'll be buying a "few" more to get to that level at least.  Good to know.