Nothing displayed, but Right-Click works. Some computers only.

This project of mine, the TcNo Account Switcher is being plagued by an issue that affects... some people.
The WebView2 window works perfectly. A handful of computers display nothing but the form's background, even when the page is changed, and can be interacted with (Both elements on the page, and the Right-Click window for the Inspector).

It affects both Windows 7 - issue #45 and Windows 10 users. Windows 10 I can't link as they contacted via Discord, but it's been 2 or 3 users so far.
Nothing is different in the builds. They work, and on some computers, they don't. I can't recreate it, but I need to solve it.

I tried 'fixes' from https://github.com/MicrosoftEdge/WebView2Feedback/issues/1077, in https://github.com/TcNobo/TcNo-Acc-Switcher/commit/1c085cede0efa315202a1a985271fd8d179eb696. But they came to the same result. Not fixing anything.

Version
SDK: WebView2 1.0.864.35, WebView 2 1.0.902-prerelease. ASP.NET Core + Desktop Runtime 5.0.8.
Runtime: WebView2 Runtime 91.0.864.70 (Latest)
Framework: WinForms
OS: Windows 10 latest, Windows 7 latest.

Repro Steps
I have no steps as nothing is done differently on computers where it works, and where it doesn't. Some just don't display anything, some do. It should open up and display everything as normal, but for some, it just doesn't.

Screenshots
Expected:

Actual, on PCs affected by this bug:

Additional context
You're able to download it yourself, here. The installer installs all required runtimes, so nobody is missing anything causing this issue.

AB#34786782

Start by reproducing the linked 2021-07-14 release on affected Windows 7 and Windows 10 systems, then compare the WebView2 runtime and SDK versions listed in the report. Review the attempted changes in commit 1c085cede0efa315202a1a985271fd8d179eb696 and the linked WebView2 feedback issue; done means the page renders normally on affected computers without breaking right-click inspection.