@ Sumit Chourey, 
The invoice was first processed in Draft, then I validated it. This is when the green banner "paid" appeared on it.  I then reverted them all to Draft status.
I see this in Accounting App > Customers > Invoices

@ Sudhir Arya

These are the journal lines I have

For CHF :

     1100 Receivables Swiss      CHF 0.00 DR         CHF 0.00 CR  (why this redundant line?)
     3400 Income Swiss             CHF 0,00 DR         CHF  524.16 CR  (happy with conversion)
     1100 Receivables                CHF 524.16 DR     CHF 0.00 CR   

  For EUR:

     1101 Receivables Euro       CHF 0.00 DR         CHF 0.00 CR (why?)
     3401 Income Euro              CHF 0.00 DR         CHF 2,086.35 CR (conversion ok)
     1101 Receivables Euro       CHF 2,086.35 DR   CHF 0,00 CR 
     1100 Receivables Swiss      CHF 0.00 DR          CHF 0.00 CR (why?)
     1100 Receivables Swiss      CHF 0.00 DR           CHF 0.00 CR (why?)     

For GBP :

      1100 Receivables Swiss       CHF 0.00 DR         CHF 0.00 CR (why?)
      3402 Income UK Pounds     CHF 0.00               CHF 168.38 CR (conversion ok)
      1102 Receivables UK Pounds CHF 168.38 DR   CHF 0.00 CR 
      1100 Receivables Swiss       CHF 0.00 DR          CHF 0.00 (why?)

I would like to see the outstanding amount of each invoice under the "Amount due" heading, ideally in the original currency and CHF equivalent currency.  I do not understand these extra journal lines, I do not think they should be there in the first place. Or if they should, what are they for?