What is real world experience with range when using a mobile phone as remote control for a Spark?

My experience is about 20 feet under ideal conditions:
- Remote location with little/no wifi interference (my phone sometimes detects 1-2 other access points with marginal signal strength)
- Straight line of site (no obstacles)
- In continental USA so should be in FCC mode

I've tried both 2.4 and 5.8 ghz, same result.

I've tried 2 different phones (samsung s4 and s7), same result.

I've tried different grips and different orientations of the phone, same result.

I've also noticed that the wifi signal strength icons for Android and for DJO GO 4 are substantially different.  When phone is a couple feet from Spark, the phone shows 4 bars and DJO GO 4 shows about 2.  At 15-20 feet when I start getting signal strength warnings, the phone shows 2-3 bars and DJI GO 4 shows 1.  I recognize they may use different scales but this seems excessive.

Common denominator seems to be the wifi antennae in the Spark.  ANyone with similar experience?  What is real world experience in terms of range when using mobile phone in USA?

Thanks,
Chris

Hello and good day Chris. Thank you for reaching out and for this inquiry. I hope that you will get the best information from our valued DJI co pilots with regards to this inquiry on there experiences in terms of range when using a mobile phone remote on there DJI Spark in USA. In addition the DJI Spark's Operating Frequency is 2.4 GHz/5.8 GHz and the Max Transmission Distance is 100 m( Distance ), 50 m( Height ) ( Unobstructed, free of interference ) when using a mobile device as a remote controller. Thank you.

Yes I have seen the 100m specification for ideal conditions.  However I am getting less than 10% of the theoretical range.  What else should I do to diagnose?

I understand the theoretical range is 100m and that actual range will probably be less depending on conditions. However under pretty good conditions (described above) I am getting less that 10% of the theoretical maximum and am trying to diagnose why.  My theory is that it's a defective wifi receiver/antenna in the Spark.  That might explain why my android OS thinks the wifi signal is strong (3-4 bars reflecting a strong signal from Spark to phone) but the Spark thinks the signal is weak (1 bar displayed in DJI GO 4 app reflecting a weak signal from Phone to Spark).

Is it true that the signal strength displayed in DJI GO 4 application is actually the signal strength being reported by the Spark receiver (versus signal strength from the Phone receiver)?  Please advise.

I don't fly my Spark without the remote, but I have found that the DJI Go app gives a good indication of the signal strength being experienced by my Spark.. When I get down to 1 bar, I usually notice video break up and sometimes significant delays in response.