Why lora server doesn't respond the first join request?

Hi there,
I had strange experience, the network server doesn’t respond the first join request? moreover, it doesn’t show all uplinks, but I can see the uplinks in the gateway log. I set it on 10 sec on sf7, 125khz bw and eu868MHz.
I have set join frequency on channel 0;

Hi, I can imagine that if you use LoRaWAN version 1.0.4 your DevNonce counter is not kept by the device trying to do OTAA. In LoRaWAN 1.0.4 the device must keep a counter (DevNonce), that for every new OTAA must increase. So if your devices always starts at 0 it needs to count up until is has reached the value from the last successful OTAA join, as chirpstack keeps track of the current DevNonce. I think this was implemented to mitigate replay attacks during join procedures.

yes, I use LoRaWAN 1.0.3.
do you mean devNonce increasing by one or just increasing? in other words, devNonce should be incremented by one?
last successful join request devnonce is 64435 (which is responded), in the next time trying (by device resetting), the next successful is 63182!!
I have checked, increasing devNonce is not considered every time, you can see two join request devnonce in picture below:

I have used Beelan-Lorawan firmware on the node and it increases devnonce, but it starts from lower value when reaches overflow, for example the devnonce value for a few join requests are as below:
16807, 19399, 3473, 18143, 64435 (successful join response is generated after this join request)
why doesn’t the server response the first join request?

edit: moreover, it’s relevant I have high data loss in uplinks.

as what you said @LanMarc77 and what brocaar said in this link I have saved the devnonce in eeprom and update for after rejoins.
the issue is resolved!
thank you and brocaar.