Android Chrome eats LOTS of background mobile data on my phone. This is despite the fact that in Android setups I DISALLOWED Chrome to use background data (i.e., Settings -> Connections -> Data usage -> Mobile data usage -> Chrome -> the toggle "Allow background data usage" is "off").
My mobile data usage comes from a single web site where I listen to audio books. I keep only that single tab open in Chrome. Normal data usage from that site is around 0.5 ... 1 MB foreground data per minute and zero background data. However, on some random days (every 2-5 days) I find that Chrome used up LOTS of background data, at a rate around 10 ... 30 MB background data per minute.
This happened, for example, on Sept 25, 2019 -- see the following two screenshots. The time difference between them is 8 minutes. In those 8 minutes, Chrome (with a single tab open), used 10 MB foreground data and 130 MB of background data. This, despite the fact that "Allow background data usage" toggle was "off".
See another screenshot of Sept. 18 2019 showing data usage by Chrome. Note that between September 8th and 18th, Chrome used 1.8 GB background mobile data in addition to using 0.2 GB foreground mobile data. The toggle "Allow background data usage" has been "off" since before Sept. 8th.
My phone: Samsung S7 SM-G930T T-Mobile with latest T-Mobile stock Android 8.0 load.
Any help would be appreciated!