@Maybelle_S  Thank you for your response.

When I posted this, it appeared to me that QBO was functioning as it was intended, it just functioned poorly. When I choose a Product/Service from the pulldown menu on the line item of a Billable Expense, it immediately deletes the Description and zeroes the Amount. I did not think this was a malfunction.

This has been how it has functioned for more than a year, across three different browsers.

To be sure, I did test it twice, as you suggested, both in a private window (Firefox) and incognito (Chrome). Same result. 

I still don't believe this is a malfunction. If it were, that would be great, because then I would ask what QBO will do to get it fixed. If this is a malfunction, please be clear and confirm that QBO is not supposed to function this way.

If however, as I suspect, this is another instance where two QBO functions do not work well together, I would appreciate hearing of any workaround or some other approach that might be better.