It seems this bug is months old. It occured today after applying the new patch on PS4. When I hit "o". The pipboy does not appear. If I am in power armor, the pipboy display does appear. The problem seems related to the VATS upgrade on the power armor helmet. I'm not certain but it seems all saves before I applied this upgrade, have the PIP boy working. The issue occured right after applying the most recent update.
Given that I need the pip boy for inventory, mapping, and questing, the game is completely broken for me. I can't use the power armor PIP boy to change apparel items so, it's completely broken there too.
I did an extensive search on this bug and to my chagrin, it's been around for a while. The more disappointing aspect is that I didn't see it addressed once by Bethesda with the exception of one request from Bethesda to a user to "private message me".
I have been playing Destiny for the last 2 years.. The customer support and response to bugs from Bungie was amazing. When there was a bug, this glaring, it was openly recognized, and at least acknowledged as under evaluation. C'mon guys, remember the fans. It's about more than the initial sale.
I guess, I'm going back to Destiny until this is fixed. If The Division roles out before then, then I'll be sad that Fallout 4, wasn't completed like 1,2 and 3.