I'm having problems again...

My blocks are now 10 days old but the wallet keeps reporting that I don't have mature coins, therefore it won't stake

Any ideas?
If not already , enable coin control
Click on settings, click options, click display, place a checkmark beside Display Coin Control , click OKClick Send Coins, Click Inputs, Click
+ sign ,
This expands the windows, so you can see the actual date & time the block was created.
What Date & time is reported there?

FYI:
Also may sure your wallet is not locked.