Why Asterisk does not respond the registration requests?

I am trying to create a softphone as a SIP account in Linphone, to be able to use it through the Asterisk program. However, the account cannot be created even though I have entered the correct IP address etc. Registration logs can be viewed on Asterisk, but Asterisk does not respond to registration requests and account creation cannot be completed. Why is this happening and what should be done?

Packages received from Asterisk server with tcpdump:

IP 192.168.1.38.sip > 192.168.1.42.sip: UDP, length 658
E..............&...*.......REGISTER sip:192.168.1.42 SIP/2.0
Via: SIP/2.0/UDP 192.168.1.38:5060;branch=z9hG4bK.q3ZZ0XJ2x;rport
From: <sip:6002@192.168.1.42>;tag=DVR5Yfpot
To: sip:6002@192.168.1.42
CSeq: 80 REGISTER
Call-ID: iNDNPFxfC3
Max-Forwards: 70
Supported: replaces, outbound, gruu
Accept: application/sdp
Accept: text/plain
Accept: application/vnd.gsma.rcs-ft-http+xml
Contact: <sip:6002@192.168.1.38;transport=udp>;message-expires=604800;+sip.instance="<urn:uuid:95e2a2cb-7e90-00b6-a052-7e536bff8e24>";+org.linphone.specs="lime"
Expires: 3600
User-Agent: Linphone Desktop/4.4.1 (USER1-PC) Windows 10 Version 2009, Qt 5.15.2 LinphoneCore/5.1.19-1-g6cdd0918e
 

IP 192.168.1.37.sip > 192.168.1.42.sip: UDP, length 715
E..............%...*........REGISTER sip:192.168.1.42 SIP/2.0
Via: SIP/2.0/UDP 192.168.1.37:5060;branch=z9hG4bK.lQcu7mUYn;rport
From: "user2" <sip:6001@192.168.1.42>;tag=FkJlLMBxa
To: "user2" <sip:6001@192.168.1.42>
CSeq: 30 REGISTER
Call-ID: -R17Cn~hEw
Max-Forwards: 70
Supported: replaces, outbound, gruu
Accept: application/sdp
Accept: text/plain
Accept: application/vnd.gsma.rcs-ft-http+xml
Contact: "user2" <sip:6001@192.168.1.37;transport=udp>;message-expires=604800;+sip.instance="<urn:uuid:7203b7a1-6f85-0023-b0c3-9280f220e73c>";+org.linphone.specs="ephemeral/1.1,groupchat/1.1,lime"
Expires: 3600
User-Agent: Linphone Desktop/4.4.1 (LAPTOP-MOI38E8S) Windows 10 Version 2009, Qt 5.15.2 LinphoneCore/5.1.19-1-g6cdd0918e

Is a firewall in place on the system (tcpdump occurs before the firewall so it can give the false impression that a firewall such as iptables is not the problem)? Which SIP channel driver are you using? Do the REGISTER requests show in Asterisk (sip set debug on or pjsip set logger on)?