Brave rewards on mobile seem to be very less per ad

On my Android mobile, it seems like the rewards i am getting are really small per ad

so far this month showing 35 ads received, and estimated rewards are 0.12 BAT
While on my desktop Brave instance, the pending rewards ar emuch higher for similar amount of ads
this has been happening on my mobile for last few months. hundreds of ads but only 1 or 2 BAT each month even though desktop is earning much higher rates


Attaching screenshot here