Windows 10 64bit, AMD RX480 8GB GPU w/ 19.2.1 driver
FX6300 CPU, 12 GB RAM...
Broken in 2.80 (0b6dbbc306b0, 2019-02-10)
Geometry>normal node gives incorrect normal for backfacing faces in Eevee when feeding it into nodes.
This does not happen with a node's default normal, or the geometry>true normal.
Here's a picture:
The rightmost sphere and planes are noticeably darker and have some issues with the shading. The right pair of objects uses geometry>normal, the left pair has the normal disconnected (left to default).
Here's a blend: