Context: CEP is defined as the radius of a circle, centered on the mean, whose perimeter is expected to include the landing points of 50% of the rounds (Wikipedia.)
According to the Teseo's datasheet, this module could reach 1.5m CEP with a roof antenna on a open sky location. When I tested my own module on a sunny day with open sky environment, I only got 6.12m CEP. I used an Abracon APARM1804-SG3 patch antenna.
This is how I assembled the antenna on my board:
Since I'm using a different type of antenna (the patch antenna one,) does the antenna type matter? If yes, why and how did it affect my measurement? I can't find any literature or article that explains about this.
EDIT #1
Here's the screenshot for the relevant section and link to the datasheet: