I have been having this issue for over 10 years.  QuickBooks has never been able to solve it - nor do they seem interested in solving it.  It doesn't matter how many times I adjust the columns, within four entries the columns are already moving.  I don't need a quantity column that is bigger than my description column!

Apparently, QuickBooks is NOT designed to have the columns stay in place.  Otherwise, this issue would not be consistently happening.