I have a Particle Boron LTE running 6.2.1 and it keeps getting an error in connecting to the Particle cloud. It was connected a few years ago but was recently unclaimed by a co-worker so that I could claim it and assign it to my account.
Here is a startup log of the device:
0000025849 [ncp.at] TRACE: < CONNECT 150000000
0000025849 [net.ppp.client] TRACE: PPP phase -> Initialize
0000025850 [net.ppp.client] TRACE: PPP phase -> Establish
0000025851 [lwip.ppp] TRACE: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x5852583b> <pcomp> <accomp>]
0000026003 [lwip.ppp] TRACE: rcvd [LCP ConfReq id=0x0 <asyncmap 0x0> <auth 0xc223 05> <magic 0xd1e797af> <pcomp> <accomp>]
0000026006 [lwip.ppp] TRACE: sent [LCP ConfNak id=0x0 <auth pap>]
0000026007 [lwip.ppp] TRACE: rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0x5852583b> <pcomp> <accomp>]
0000027262 [lwip.ppp] TRACE: rcvd [LCP ConfReq id=0x1 <asyncmap 0x0> <auth pap> <magic 0xd1e797af> <pcomp> <accomp>]
0000027263 [lwip.ppp] TRACE: sent [LCP ConfAck id=0x1 <asyncmap 0x0> <auth pap> <magic 0xd1e797af> <pcomp> <accomp>]
0000027264 [lwip.ppp] TRACE: sent [LCP EchoReq id=0x0 magic=0x5852583b]
0000027265 [net.ppp.client] TRACE: PPP phase -> Authenticate
0000027265 [lwip.ppp] TRACE: sent [PAP AuthReq id=0x1 user="" password=""]
0000028542 [lwip.ppp] TRACE: rcvd [LCP ConfReq id=0x2 <asyncmap 0x0> <auth pap> <magic 0xd1e797af> <pcomp> <accomp>]
0000028543 [lwip.ppp] TRACE: sent [LCP ConfAck id=0x2 <asyncmap 0x0> <auth pap> <magic 0xd1e797af> <pcomp> <accomp>]
0000029822 [lwip.ppp] TRACE: rcvd [LCP ConfReq id=0x3 <asyncmap 0x0> <auth pap> <magic 0xd1e797af> <pcomp> <accomp>]
0000029823 [lwip.ppp] TRACE: sent [LCP ConfAck id=0x3 <asyncmap 0x0> <auth pap> <magic 0xd1e797af> <pcomp> <accomp>]
0000031102 [lwip.ppp] TRACE: rcvd [LCP ConfReq id=0x4 <asyncmap 0x0> <auth pap> <magic 0xd1e797af> <pcomp> <accomp>]
0000031103 [lwip.ppp] TRACE: sent [LCP ConfAck id=0x4 <asyncmap 0x0> <auth pap> <magic 0xd1e797af> <pcomp> <accomp>]
0000032265 [lwip.ppp] TRACE: sent [LCP EchoReq id=0x1 magic=0x5852583b]
0000032275 [lwip.ppp] TRACE: rcvd [LCP ConfReq id=0x5 <asyncmap 0x0> <auth pap> <magic 0xd1e797af> <pcomp> <accomp>]
0000032276 [lwip.ppp] TRACE: sent [LCP ConfAck id=0x5 <asyncmap 0x0> <auth pap> <magic 0xd1e797af> <pcomp> <accomp>]
0000032416 [lwip.ppp] TRACE: rcvd [LCP ConfReq id=0x6 <asyncmap 0x0> <auth pap> <magic 0xd1e797af> <pcomp> <accomp>]
0000032417 [lwip.ppp] TRACE: sent [LCP ConfAck id=0x6 <asyncmap 0x0> <auth pap> <magic 0xd1e797af> <pcomp> <accomp>]
0000033266 [lwip.ppp] TRACE: sent [PAP AuthReq id=0x2 user="" password=""]
0000033277 [lwip.ppp] TRACE: rcvd [LCP DiscReq id=0x7 magic=0xd1e797af]
0000033279 [lwip.ppp] TRACE: rcvd [PAP AuthAck id=0x2 ""]
0000033279 [net.ppp.client] TRACE: PPP phase -> Network
0000033280 [lwip.ppp] TRACE: sent [IPCP ConfReq id=0x1 <addr 0.0.0.0> <msdns1 8.8.8.8> <msdns2 8.8.4.4>]
0000033664 [lwip.ppp] TRACE: rcvd [IPCP ConfReq id=0x0]
0000033665 [lwip.ppp] TRACE: sent [IPCP ConfAck id=0x0]
0000033667 [lwip.ppp] TRACE: rcvd [IPCP ConfNak id=0x1 <addr 100.76.216.170> <msdns1 8.8.4.4> <msdns2 8.8.8.8>]
0000033668 [lwip.ppp] TRACE: sent [IPCP ConfReq id=0x2 <addr 100.76.216.170> <msdns1 8.8.4.4> <msdns2 8.8.8.8>]
0000034945 [lwip.ppp] TRACE: rcvd [IPCP ConfAck id=0x2 <addr 100.76.216.170> <msdns1 8.8.4.4> <msdns2 8.8.8.8>]
0000034948 [system.nm] INFO: State changed: IFACE_UP -> IFACE_LINK_UP
0000034949 [net.ppp.client] TRACE: PPP thread event UP data=0
0000034950 [net.ppp.client] TRACE: State CONNECTING -> CONNECTED
0000034950 [system.nm] INFO: State changed: IFACE_LINK_UP -> IP_CONFIGURED
0000034952 [net.ppp.client] TRACE: PPP phase -> Running
0000034953 [net.pppncp] TRACE: Negotiated MTU: 1500
0000035031 [system] INFO: Cloud: connecting
0000035033 [system] WARN: Failed to load session data from persistent storage
0000037551 [ncp.at] TRACE: < +CEREG: 5,"AE03","8739911",7
0000038833 [system] INFO: Cloud socket connected
0000038834 [comm.protocol.handshake] INFO: Establish secure connection
0000038837 [comm.dtls] INFO: (CMPL,RENEG,NO_SESS,ERR) restoreStatus=2
0000040975 [comm.protocol.handshake] INFO: Sending HELLO message
0000040975 [comm.coap] TRACE: Sending CoAP message
0000040976 [comm.coap] TRACE: CON POST /h size=39 token= id=1
0000045271 [comm.coap] TRACE: Retransmitting CoAP message; ID: 1; attempt 1 of 3
0000045271 [comm.coap] TRACE: Sending CoAP message
0000045272 [comm.coap] TRACE: CON POST /h size=39 token= id=1
0000049251 [ncp.at] TRACE: < +CEREG: 5,"AE03","873980F",7
0000056349 [comm.coap] TRACE: Retransmitting CoAP message; ID: 1; attempt 2 of 3
0000056349 [comm.coap] TRACE: Sending CoAP message
0000056350 [comm.coap] TRACE: CON POST /h size=39 token= id=1
0000058051 [ncp.at] TRACE: < +CEREG: 5,"AE03","8739911",7
0000073161 [comm.coap] TRACE: Retransmitting CoAP message; ID: 1; attempt 3 of 3
0000073161 [comm.coap] TRACE: Sending CoAP message
0000073162 [comm.coap] TRACE: CON POST /h size=39 token= id=1
0000118786 [comm.coap] ERROR: CoAP message timeout; ID: 1
0000118786 [comm.dtls] INFO: session cmd (CLS,DIS,MOV,LOD,SAV): 0
0000118788 [comm.protocol.handshake] ERROR: Could not send HELLO message: 10