Delivery Optimisation No longer working

Delivery Optimisation is not working as intended, I have set the relevant limits within the settings however all downloads that happen always exceed what I have set. This causes a real issue as we don't have the best internet and it completely choles the entire household of any internet to try and feed the download.

Is there any fix for this, is this a bug, it used to work perfectly fine?

I have tried all the tips to fix but to no avail, task manager clearly shows all the internet being used.