Peak on clear blue. Help please. Thanks in advance!

Today is cycle day 15 for me. I have had high fertility readings on two of my advanced cb monitors the past couple of days. This evening I had a peak reading on my first monitor, and about a half hour later I tested with new urine on my second monitor. That second monitor is still showing high fertility.

Which one should I trust? Was the urine possibly too diluted with the second monitor since I didn't wait long enough before testing the second time. Thanks in advance!