Sudden Increase in Data Usage

This month my data usage increased dramatically.  According to my router
                                Tot Mbytes     Avg Mbytes
      Today                  35460           (it's 10:20am)
      Yesterday           127446
      This week           768547           109792
      This Month       1267175            42239

      Last Month         396675            13222

Only changes have been: 
        leaving open ThinkOrSwim --- but this was true last month too
        using Discord on PC
        Windows upgraded to 11

I see no extra devices on my lan.

I'm not sure where to look for the error, thoughts?