I would occasionally have someone ask me why I opened their email 20+ times before responding (I didn't).
After a while, I realized that when using the "arrow down" key to scroll through your inbox in Apple Mail (with split view enabled), Apple Mail will open and render every email in the split view when attempting to open an email further down in the inbox. This would result in every tracking pixel being loaded/rendered dozens of times, even when the email was open on the screen for < 200ms.
After a few times hearing people ask why I opened their email dozens of times but haven't responded (when really hadn't read their email at all), I ended up disabling images from loading in emails entirely.
Does anyone know if this is still an issue with Apple Mail? Or if this also happens with Gmail configured in split view?
What issue? This is marketing wonks and creepy SV companies abusing image loading in email to implement "read receipts". The fact that some clients load images differently is their problem, not Apple's.
IMO the people harassing you about how many times you opened their email are idiots. Image-based open tracking is notoriously unreliable and is best used to track engagement trends within a given audience, not as a microscope on one person.
This seems like a classic example of people taking some marketing feature at face value and not spending any effort to understand the actual technology under the metrics they see in a dashboard.