When using the "chameleon" armor mod, it causes 2 visual bugs:

1) the pip boy will either disappear entirely and not be visible or will be partially visible but not always 100% functional
2) weapons become invisible making the sites mostly useless - scopes still work fine but not sights.

p.s.

Thanks for the amazing game guys!

This happens with me as well, both points. The second point is more prevalent with iron sight scopes with dot sights. Full scopes like sniper scopes are unaffected by this.

Yup have the same issue, I have found though, looking at the sky when activating the pipboy when in predator mode, for me 99% of the time works and displays the pipboy. The biggest issue is the second, scope reticles don't show up so you have to kinda guess where to fire. You can use the iron sighting for the horizontal but it's a bit hit and miss with the vertical aiming especially with the open holo sights.