5 months issue, what i am doing wrong

I am going to explain my installation + configuration, if anyone can help me on solve this issue I will be very appreciated, 5 months working on finding solution on it and issue still persist

INSTALLATION:

 1 - 10 meter hight pole with 410-470 mhz antenna 
 2 - cable down to radio transmitter
 3 - 35 db radio using Trimtalk protocol
 4 - radio is connected to Esp32 with EspRtk software injecting messages ( 1007,1008,1033)
 5 - Ublox f9p generating RTCM messages (1005, 1077,1087, 1230)
 6 - cable connected to F9P and up to GNSS Antenna L1+L2 gps+glonass by Unistrong UA45

F9P FIXED POSSITION

  we set the f9p at 1 minute 4 meters also set 24 hours at 0,20 m,  both time getting fixed position ok and working 100%

COMMUNICATION AND MESSAGES OUT

   1- Mesages from F9P out  ok, (1005,1077, 1087, 1230)
   2 - Esp32 receiving them ok and injecting 1007,1008, 1033 out
   3 - All mesages our from Esp32 (1005, 1007, 1008, 1077, 1087, 1230, 1033)  seems working fine on SNIP we have tested and all ok, synchronized and ramdom 100%

  EQUIPMENTS USED FOR TESTING

 1- we are using Trimble CFX 750 , Trimble 372, and we also have 1 ublox F9P set as rover.

 2 - in my experience By testing the RTL POSITION CORRECTION  on these Trimble equipments if I set the cable directly from EsP32 to them RTK POSITION CORRECTION comes on around 3-5 minutes and 1-2 Minutes at second time. 
     So if I take the cable disconnected from them RTK POSITION CORRECTION drops after 1 minutes, if I connected the cable back RTK CORRECTION should come back right the way.
   
  ISSUE

      1 - BY radio link all messages we are receiving ok by receiving radio, but....  on Trimble 372 antenna set for receiving in RTCM messages, all configurated ok RTK POSSITION gets on but keeps dropping from time to time, lets say 5 minutes ON then 5 minutes OFF,  sometimes RTK POSITION just get off forever.

     2 - At first we thought the issue could be on the radios so we took all equipments to tech laboratory for testing and same issue happens, RTK POSITION ON  and OFF  5 minutes each.  

     3 - we have changed the f9p modules, used diferent interfaces, also we have changed radios and issue still there

POSSIBILITIES

  after all these Months testing it unsuccessfully,  I believe the last possibility may be the GNSS Antenna, but we also have changed it twice with same model.   But the weird thing is that some guys around have issued small antennas as well and had great success on this.

 so I will be very happy if anyone around could help me on this.