Unable to switch to loiter/ position hold mode

I’m getting unusual two “beeps” when trying to switch from stabilize or althold to loiter mode(also to poshold). I have tuned all my axes, except yaw. Checked vibrations- all seems really good. Has anyone had similar issue?
My setup:
Pixhawk cube
heree+ gps
emax rs2205 2600kv motors
dys blheli 20a escs
No lidar is attached( I could use lidar LW20, if really needed)(space problems)

No of lines 87604
Duration 0:04:08
Vehicletype ArduCopter
Firmware Version V3.5.7
Firmware Hash b11c6af3
Hardware Type
Free Mem 0
Skipped Lines 0
Test: Autotune = UNKNOWN - No ATUN log data
Test: Brownout = GOOD -
Test: Compass = GOOD - mag_field interference within limits (6.52%)

Test: Dupe Log Data = GOOD -
Test: Empty = GOOD -
Test: Event/Failsafe = FAIL - ERR found: FLT_MODE
Test: GPS = GOOD -
Test: IMU Mismatch = GOOD - (Mismatch: 0.38, WARN: 0.75, FAIL: 1.50)
Test: Motor Balance = WARN - Motor channel averages = [1483, 1465, 1392, 1384]
Average motor output = 1431
Difference between min and max motor averages = 99
Test: NaNs = GOOD -
Test: OpticalFlow = FAIL - FAIL: no optical flow data

Test: Parameters = FAIL - ‘THR_MIN’ not found
Test: PM = FAIL - 22 slow loop lines found, max 10.93% on line 48003
Test: Pitch/Roll = GOOD -
Test: Thrust = GOOD -
Test: VCC = GOOD -

Here is the log .bin file:

and here is the param file:


You are attempting to use a guided mode before the EKF is happy with the GPS lock.
Just because it says 3D Fix does NOT mean it is ready for guided modes.

On the ground before arming, with a 3D fix, switch to Loiter.
If the LED goes from flashing green to flashing blue, and you get your 2 beeps, the 3D fix is not good enough.
And maybe even wait some more.
When you can switch to a guided mode and the LED stays green, single beep, you are good to go.

Problem solved, thanks Mike! Was dumb enough to tape my RC receiver on top of the gps. That blocked the signal…