On project upgrade, SubImageIndex breaks until you re-assign SubUV Animation

On project upgrade, SubImageIndex breaks until you re-assign SubUV Animation

Attached project is a 4.11 project, you'll need to Open a Copy in 4.12 or 4.13

1. Download the attached project (includes a particle system with two SubImage emitters)
2. "Open a Copy" of the project in 4.12 (or 4.13)
3. Open the emitter and look at the viewport
4. Go to the second emitter's SubImage Index module
5. Re-assign the exact same SubUV Animation that is already present

Result: Emitter on the right is broken at step 3
Expected: Both emitters still work properly without having to re-assign the SubUV Animation

Sub UV Animation from 4.11 to 4.12 (particle trimming) stops working