Master Properties & Scripting Bug - randomly changing properties even when keyframed
AEP Setup: A large number of instances of a comp rigged with Master Properties. set up to randomly (and persistently) select between a number of face illustrations, all with 3 checks (or x's). In the comp containing the instances, scale, rotation & position, and 3 Check MPs are controlled via expressions that use luminance of another layer to control a size bump & a wave where all the X's turn into checks.
Problem: Even when keyframed and with expressions disabled, some checks flicker back and forth between checks & x's. Problem can be seen starting at 0:00:27:03 in the 'Where It's Breaking - Not Working' comp. Doesn't happen on every comp, just some.
Solution: With Continuous rasterization enabled on every single instance of the MP Comp, the problem sorted itself out. However, this really killed both the working speed in the comp (which was already quite heavy), and the render speed.
Attempted Solutions that did nothing: Restarting AE, Restarting Comp, Moving Cache locations, Clearing cache & image memory, keyframing properties, importing AEP into a new project.
Hardware: Apple 15.4" MacBook Pro with Touch Bar, 2.9GHz 6-Core Intel Core i9, 32GB RAM, 512GB SSD, Radeon Pro 560X, Space Gray (Mid 2018), Mojave 10.14.2, Cache on 1TB external SSD.
Also tested on Late 2015 iMac Retina 5K w/ 4GHz Intel Core i7, 16GB 1867 MHz DDR3 on Sierra 10.12.6 w/ local cache. same error occurred.
Software: AE 16.0.1
Glad to provide any other information you might need, although I tried to be quite thorough with this writeup :)
Can't attach a file because it's client work, but I emailed directly to Tim.