Thanks for the suggestions...
I backed up the file. I cut the paycheck transaction from my checking account. Both entries in my retirement account were removed. When I pasted it back, both entries returned.
I probably used the paycheck wizard years ago when I first set this up. My employer only makes their contribution twice a year, in March and October. The duplicate entries only started with my paycheck of 2/15/19. I believe that was just after R18.15 installed.
It wouldn't bother me if that was the way it had always been. But this just started with my last paycheck. I do remember when I entered my 2/15 paycheck, it did ask me something about if this transaction included a 401k contribution and I said Yes. However I have no idea how to change that. I tried deleting the check and then changing the date of my next paycheck and re-entering it, but it did not ask me about 401k contributions and did make a duplicate zero amount entry.
As you suggested I added an employer match of $1 and you are correct. I had two entries, one for my contribution and one for the employer and no zero amount transaction. I have no idea why Quicken would make such a ridiculous change to add an employer match transaction that has a value of zero.