GPS L86 GPS accuracy noise

IoT Modules GNSS Module
1

Hi, I’m building an application that use BLE, GPS L86, moduleSim.
According to GPS L86 it can reach accuracy aproximate <5m in open sky.
But when I integrate my GPS L86 with nRF module (BLE), module sim (Sara u201)
=> GPS L86 has very bad accuracy (it’s about “1km” from the real address in “open sky”)
1km is too bad.
So I have some questions

  1. If I have just bought GPS L86 and test it stand alone, if it can reach as datasheet <5m in open sky ? Without any configurations ? or Should I need some configurations to reach best performance ?
  2. May radio signal from BLE and Module Sim affect to my GPS module ? I followed GPS L86 hardware design to keep a distance with these module but 1km is too bad.
2

Dear Sir,
Here is a topic which is similar to your question.
For reference : Gps l86 is about 1km away from real coordinate

Best regards.