App Version: 71.0.3578.13 Beta
iOS Version: 12.0, 11.4.1, 10.3.3
Device: iPhone only

Prerequisite: 
1. Enable ‘#out-of-web-fullscreen’ flag from chrome://flags
2. Enable ‘#browser-container-fullscreen’ flag from chrome://flags

Steps to reproduce:
1. Launch chrome app and set the above mentioned flags
2. Cold start the app
3. Open a new incognito tab from popup menu

Observed results:
Notice that a white screen is displayed for a second before displaying the incognito tab

Note: Issue doesn’t exist on opening new incognito tab from tab switcher

Expected results:
No white screen should be displayed on opening an incognito tab

Number of times you were able to reproduce: 5/5
Bug reproducible after clean install: Yes
Bug reproducible after clearing cache and cookies: Yes
Bug reproducible on Chrome Mobile on Android: Not tested
Bug reproducible on Safari/Firefox: Firefox: No, Safari: No
Bug reproducible on current stable build (App Version, iOS Version): NA on M69 
Bug reproducible on the current beta channel build (App Version, iOS Version): Yes on M71 Beta (Feature available from M71)

Link to video:
https://drive.google.com/file/d/14Lxkhld6HkbRsF09wvtk-FfLsEPgTmza/view?usp=sharing