Hardware rendering causes window not to be drawn

In rare cases, when AA_UseDesktopOpenGL is set to true, the following symptoms appear:

• Main window isn't drawn (is just a white/black square)
• App stops writing to log file

Some additional facts:

• The main window displays has a QtWebEngine
• At least some other functionality in the app continues.
• The 6 reported cases we've seen (there are many more) have all been on Windows and all have Nvidia GeForce cards.

It's at least not only driver related. From our telemetry we can see that the drivers that those 6 are using are some of the most reliable drivers.

This is the information we have about the video cards and the drivers:

• description: "NVIDIA GeForce RTX 2080 SUPER" vendor_id: 4318 device_id: 7809 revision: 161 video_memory: 3221225472 driver { date: "7-5-2020" vendor: "NVIDIA" version: "27.21.14.5167" }
• description: "NVIDIA GeForce GTX 1050 Ti" vendor_id: 4318 device_id: 7298 revision: 161 video_memory: 3221225472 driver { date: "12-11-2020" vendor: "NVIDIA" version: "27.21.14.6089" }
• description: "NVIDIA GeForce RTX 2080 Ti" vendor_id: 4318 device_id: 7687 revision: 161 video_memory: 3221225472 driver { date: "12-3-2020" vendor: "NVIDIA" version: "27.21.14.6079" }
• description: "NVIDIA GeForce RTX 2070 SUPER" vendor_id: 4318 device_id: 7812 revision: 161 video_memory: 3221225472 driver { date: "7-5-2020" vendor: "NVIDIA" version: "27.21.14.5167" }
• description: "NVIDIA GeForce RTX 2080 SUPER" vendor_id: 4318 device_id: 7809 revision: 161 video_memory: 3221225472 driver { date: "4-23-2021" vendor: "NVIDIA" version: "27.21.14.6627" } }
  gpus { description: "NVIDIA GeForce RTX 2070 SUPER" vendor_id: 4318 device_id: 7812 revision: 161 video_memory: 3221225472 driver { date: "8-12-2020" vendor: "NVIDIA" version: "27.21.14.5206" }

From our telemetry we can also see that sessions using those drivers are very likely to have activity that tells us the UI is working. In fact 4 of those 5 drivers (all except 5167) are among top 10 most likely to have such activity.

(According to https://www.tenforums.com/graphic-cards/139746-what-do-numbers-nvidia-driver-mean.html
The drivers are all for WDDM 2.7, the same DirectX version, same Nvidia driver baseline but (5) different versions of drivers).

Previously mentioned in a forum post.