Tooltips rapidly close - existing WPF 4.8 application - some computers only

### Description

This problem is specific to certain PCs, and I am looking for advice how to narrow down the cause. The problem has emerged for an existing compiled WPF 4.8 application, seemingly triggered by certain system updates.

Problem: certain Tooltips will rapidly flash on/off. This is similar to other tooltip issues here but none were for .NET Framework 4.8. (https://github.com/dotnet/wpf/issues/7489, https://github.com/dotnet/wpf/issues/6710, https://github.com/dotnet/wpf/issues/6852, https://github.com/dotnet/wpf/issues/6289, https://github.com/dotnet/wpf/issues/6220)

In one example we had a user whose PC was updated from Windows 10 to 11; no problem before the update, problem occurs after the update. Something relevant must have changed -- but what?

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I will gladly add any additional information about my application or system details that might be useful. But I'm not sure what to do next to figure that out.

### Reproduction Steps

My application consistently shows the problem on some computers but I have not yet been able to create a small repro that also does so.

On PCs with this issue, when the user mouses over certain custom controls (derived from `Control`) the problem happens. Other controls have no problem.

### Expected behavior

Tooltip remains visible.

### Actual behavior

Tooltip briefly appears/disappears.

Using WPF Snoop the following events all are logged at the same moment:

### Regression?

Yes

### Known Workarounds

None

### Impact

We use the tooltips to summarize some info that the user otherwise can only access with many more steps.

### Configuration

System info... may or may not be relevant:

From computer C **without** the issue:
- `RuntimeInformation.FrameworkDescription = ".NET Framework 4.8.4739.0"`
- `System.Environment.Version = "4.0.30319.42000"`
- OS Name Microsoft Windows 10 Enterprise
- Version 10.0.19045 Build 19045

From computer D **with** the issue:
- `RuntimeInformation.FrameworkDescription = ".NET Framework 4.8.9277.0"`
- `System.Environment.Version = "4.0.30319.42000"`
- OS Name Microsoft Windows 11 Enterprise
- Version 10.0.22631 Build 22631

From computer J **without** the issue:
- `RuntimeInformation.FrameworkDescription = ".NET Framework 4.8.9277.0"`
- `System.Environment.Version = "4.0.30319.42000"`
- OS Name Microsoft Windows 11 Enterprise
- Version 10.0.22631 Build 22631

Note that D and J are the same so I'm obviously missing some key distinguishing detail.

### Other information

_No response_