Signal lost during the day, but works at night

Greetings, I am wondering if you can shed some light on this strange situation. We have a WisBlock RAK4631 installed at a location where it has been working fine for multiple months. However, in the last 2-3 days, the unit can’t reach the gateway beginning at 7:30am, and then fails to reach the gateway all day. When night falls, it starts to work again.

I took another RAK4631 to the same location and tried to connect. It was also unable to connect during the day.

The unit is 4.5km away from gateway unit.

The location is near to some large factories. Does this sound like interference being broadcast by something in a factory, since the problem begins at the same approximate time each day, or might this be related to foliage (it is springtime here, and trees are beginning to produce leaves, and this unit is in an area of dense trees.)

The unit is within 0.5km of two other RAK4631 units which are continuing to work fine. One of these units is even further from the gateway, and the other is slightly nearer.

I am going to try an antenna with higher gain at that location to see if it helps.

Any suggestions welcome.

Thanks

Hopefully the antenna change will help your situation.

Another experiment you can try is to swap the working RAK4631 0.5km away and see if it will behave normal. If that is the case, it might not be the environment but specific to the module misbehaving during daytime.