When my account did not have enough NET resource ( 12 bytes limit at that moment) and I sent a transaction, I got an error
transaction net usage is too high: 120 > 12
I bought NET resource and sent again the transaction which is the last one in this block.
And then I see that the used net bandwith actually grew by 120 bytes in
get account result.
My question is why is it shown
15 B in eosx.io report.