Background Safari Tab contributing to DeviceActivityMonitor usage threshold?

I am currently debugging an issue with DeviceActivityMonitor where the threshold is reached even though the target app (e.g. Instagram) is not being used actively.

I noticed that the device with the unexpected behavior had the instagram.com website opened in the Safari web browser (among hundreds of other tabs).

That tab was not actively used either (not in foreground, Safari app neither used).

However, I was wondering if it can happen that this website is contributing towards the threshold as well even though it is in background and not used?

Otherwise I cannot explain myself this strange behavior.