I'm using Chitubox V1.6.3 with an Anycubic Photon (not an S) and all the parts sliced in Chitubox are coming out roughly 5% too large. Parts sliced in the Photon's own Workshop software are correct size, but they have other issues.
My setting are as follows:
Res X: 1440px, Y: 2560px
Lock Ratio: Off
Size X: 65mm, Y: 115mm, Z: 155mm
Build Area Offset: Off
Machine Type: AnyCubic Photon
Layer Height: 0.020mm to 0.050mm - occurs with any setting
This is a problem with the lack of size compensation or "overgrowth prevention" I truly hope they add this functionality into the application, or perhaps the pro version. Without, I doubt it will be a useful platform for size-sensitive model production.