How to reproduce:
0. Reproduction steps with the screenshots are also linked in the Edit (How to Build and Run.pdf)
1. Open the attached 'msfsource.tar.gz' project from the link given in Edit
2. Open terminal
3. Enter 'sudo gem install -n /usr/local/bin cocoapods'
4. Enter '/usr/local/bin/pod setup'
5. Enter '/usr/local/bin/pod repo update'
6. Make sure that your target platform is iOS
7. Open '00_init' Scene
8. In the menu bar select Select Build -> Select Configuration
9. Once a BuilderWindow is opened, select Full Build(Code + Bundle)
10. Once the build is done, open terminal
11. In terminal navigate to Unity/build/ios/player
12. Enter 'install pod' to generate xcworkspace
13. Open 'Unity-iPhone.xcworkspace' from Unity/build/ios/player folder
14. Deploy project to an iOS 14 device or iPhone 11
15. Once app is launched accept Privacy Policy and Terms of Service
16. Skip intro by pressing 'SKIP INTRO' in the bottom left corner
17. Tap on the screen using 4 fingers at the same time to open a debug window
18. Scroll down to the 'NUE' button and click on it to open a sub menu
19. Scroll down through the submenu until you see 'Mark NUE Complete' button and click on it to attempt a soft restart
20. Tap on the screen using 4 fingers at the same time to open a debug window
21. Scroll down to the "player' button and click on it to open a sub menu
22. Drag 'Player level:' slider to the 25
23. Press 'Update' button
24. When a series of Level Up Congratulations appears click 'Continue' until it disappears
25. Tap on the screen using 4 fingers at the same time to open a debug window
26. Select '[Goods]' button
27. Scroll down to the Hero XP section and press the 'xp Lvl20' a number of times
28. Exit Debug Mode
29. Click the 'Roster' button in the top-left of the screen
30. Select Spiderman character
31. Select 'TRAIN" in the bottom-left corner
32. Drag slider of the 'Select Desired Level'
33. Click 'APPLY' button on the right side of the screen
34. Observe the fireworks particles that appear as a celebration sequence

Expected result: Particles geometry is triangulated
Actual result: Particles geometry looks like lines/rectangles

Reproducible with: 2018.4.18f1, 2018.4.25f1

Reproducible with:
iPhone X (iOS 14b5)

Not reproducible with:
iPhone 8+ (iOS 12.0)
iPhone XR (iOS 13.4.1)
iPad Air 2 (iOS 11.0.3)
iPad 9.7 6th gen (iOS 12.1)

Notes:
- Not reproduced by CQA
- Videos of the actual (incorrect_particles.mov) and expected (correct_particles.MOV) results are added to the Edit