RaspberryPi Gateway Doesn't receive all packets

I have two gateway.( RHF2S208 and RaspberryPi Gateway ). They are located in a common place. RHF2S208 receive all of packets from end-devices and send ACK to end-device but RaspberryPi Gateway isn’t stable. It receive just some packets also doesn’t send ACK.
I have used this source code for RaspberryPi Gateway: https://github.com/Lora-net/packet_forwarder
also I have used RHF0M0301 module. (This module used in RHF2S208)

How can I fix this problem?

Only one of those two (or more) gateways will be selected by the TTN network server to send an ACK (if possible: the one with the best reception quality), so that part may very well be working as expected.

What do the gateway logs show? Did you see the recommendations about keeping some minimal distance between device and gateway?

I guess that should read “RHF0M301”?

Thanks a lot, ACK issue solved.
I thought that all of gateways should send ACK packet but the next problem has not been solved yet. some of the packets isn’t received!
where is the problem from?

Try moving it to a very different place.

What sort of antenna does it have?