Not sure if it'll help but try going to Settings>PSN>Restore Licenses.PSN still isn't recognizing new PS Plus memberships. The PS App recognizes it and allows you to download free PS Plus games and add to queue, but once installed it's locked and can't be booted.
I had an error when I tried confirming Resogun in the store, when I downloaded it and installed it was locked. After doing the above, it unlocked and played it just fine.