I tried just as you this morning. Connection works well. I also get time sync rejected errors after some time. But I think it is also able to correctly do time sync. At least I still have incoming messages…
2021-09-11 08:38:46.613 [SYN:INFO] MCU/SX130X drift stats: min: +0.0ppm q50: -2.4ppm q80: -9.8ppm max: -13.8ppm - threshold q90: -11.9ppm
2021-09-11 08:38:46.613 [SYN:INFO] Mean MCU drift vs SX130X#0: -1.0ppm
2021-09-11 08:39:21.272 [SYN:INFO] Time sync qualities: min=306 q90=340 max=341 (previous q90=343)
2021-09-11 08:39:23.373 [SYN:INFO] MCU/SX130X drift stats: min: +0.0ppm q50: +6.2ppm q80: +13.3ppm max: +17.6ppm - threshold q90: +17.1ppm
2021-09-11 08:39:23.373 [SYN:INFO] Mean MCU drift vs SX130X#0: 4.0ppm
2021-09-11 08:39:35.976 [SYN:VERB] Time sync rejected: quality=371 threshold=340
2021-09-11 08:39:40.177 [SYN:VERB] Time sync rejected: quality=341 threshold=340
2021-09-11 08:40:03.282 [SYN:VERB] Time sync rejected: quality=341 threshold=340
2021-09-11 08:40:09.584 [SYN:INFO] MCU/SX130X drift stats: min: +1.0ppm q50: +3.8ppm q80: +16.7ppm max: -24.4ppm - threshold q90: -24.3ppm
2021-09-11 08:40:09.584 [SYN:INFO] Mean MCU drift vs SX130X#0: -1.5ppm
2021-09-11 08:40:22.187 [SYN:INFO] Time sync qualities: min=294 q90=341 max=371 (previous q90=340)
2021-09-11 08:40:34.790 [SYN:VERB] Time sync rejected: quality=354 threshold=341
2021-09-11 08:40:53.695 [SYN:INFO] MCU/SX130X drift stats: min: +1.0ppm q50: -3.3ppm q80: +11.4ppm max: -16.2ppm - threshold q90: +14.8ppm
2021-09-11 08:40:53.696 [SYN:INFO] Mean MCU drift vs SX130X#0: 0.7ppm
2021-09-11 08:41:02.098 [SYN:VERB] Time sync rejected: quality=347 threshold=341
2021-09-11 08:41:03.902 [S2E:VERB] RX 867.9MHz DR5 SF7/BW125 snr=-3.8 rssi=-118 xtime=0x4700000D2F54B3 - updf mhdr=40 DevAddr=26088ABD FCtrl=80 FCnt=2541 FOpts=[] 036D0C54..1E47 mic=-1989087438 (59 bytes)
2021-09-11 08:41:10.500 [SYN:VERB] Time sync rejected: quality=342 threshold=341
2021-09-11 08:41:12.600 [SYN:VERB] Time sync rejected: quality=350 threshold=341
2021-09-11 08:41:24.517 [S2E:VERB] RX 867.7MHz DR3 SF9/BW125 snr=-15.5 rssi=-125 xtime=0x4700000E69ED7E - updf mhdr=40 DevAddr=2601280E FCtrl=C2 FCnt=17965 FOpts=[0307] 0D3865CC..5189 mic=-495581456 (27 bytes)
2021-09-11 08:41:25.203 [SYN:INFO] Time sync qualities: min=295 q90=347 max=354 (previous q90=341)
2021-09-11 08:41:33.606 [SYN:VERB] Time sync rejected: quality=355 threshold=347
2021-09-11 08:41:42.008 [SYN:INFO] MCU/SX130X drift stats: min: -3.3ppm q50: -8.6ppm q80: -9.5ppm max: -20.9ppm - threshold q90: -16.8ppm
2021-09-11 08:41:42.008 [SYN:INFO] Mean MCU drift vs SX130X#0: -7.8ppm
2021-09-11 08:41:52.511 [SYN:VERB] Time sync rejected: quality=503 threshold=347
2021-09-11 08:42:13.516 [SYN:VERB] Time sync rejected: quality=353 threshold=347
2021-09-11 08:42:26.119 [SYN:INFO] Time sync qualities: min=311 q90=353 max=503 (previous q90=347)
2021-09-11 08:42:28.220 [SYN:INFO] MCU/SX130X drift stats: min: -2.4ppm q50: +7.1ppm q80: -10.5ppm max: -16.7ppm - threshold q90: -15.2ppm
2021-09-11 08:42:28.220 [SYN:INFO] Mean MCU drift vs SX130X#0: -4.1ppm
2021-09-11 08:42:55.526 [SYN:VERB] Time sync rejected: quality=380 threshold=353
2021-09-11 08:43:11.378 [S2E:VERB] RX 867.3MHz DR0 SF12/BW125 snr=8.8 rssi=-73 xtime=0x47000014C85984 - updf mhdr=40 DevAddr=260B1790 FCtrl=80 FCnt=39 FOpts=[] 02B67C6A..9DE9 mic=-1490846239 (31 bytes)
2021-09-11 08:43:11.821 [S2E:DEBU] ::1 diid=50352 [ant#0] - next TX start ahead by 4s537ms
2021-09-11 08:43:12.330 [SYN:INFO] MCU/SX130X drift stats: min: -1.0ppm q50: -2.9ppm q80: +9.5ppm max: -13.8ppm - threshold q90: -13.8ppm
2021-09-11 08:43:12.330 [SYN:INFO] Mean MCU drift vs SX130X#0: -2.0ppm
2021-09-11 08:43:16.338 [S2E:VERB] ::1 diid=50352 [ant#0] - starting TX in 19ms915us
2021-09-11 08:43:16.364 [S2E:INFO] TX ::1 diid=50352 [ant#0] - dntxed: 867.3MHz 16.0dBm ant#0(0) DR0 SF12/BW125 frame=6090170B268509000340FF00..B80695A4
2021-09-11 08:43:17.513 [S2E:DEBU] Tx done diid=50352
2021-09-11 08:43:29.135 [SYN:INFO] Time sync qualities: min=273 q90=341 max=380 (previous q90=353)
Also I got some nice logs about the temperature sensor after a while:
2021-09-11 08:46:33.984 [SYN:INFO] Time sync qualities: min=273 q90=341 max=376 (previous q90=341)
2021-09-11 08:46:42.387 [SYN:VERB] Time sync rejected: quality=629 threshold=341
2021-09-11 08:46:46.035 [S2E:VERB] RX 867.7MHz DR5 SF7/BW125 snr=14.0 rssi=-78 xtime=0x4700002193DE7D - updf mhdr=40 DevAddr=260B1790 FCtrl=80 FCnt=40 FOpts=[] 0293D7C6..4093 mic=449092140 (31 bytes)
2021-09-11 08:46:46.475 [S2E:DEBU] ::1 diid=50614 [ant#0] - next TX start ahead by 4s547ms
2021-09-11 08:46:50.789 [SYN:VERB] Time sync rejected: quality=342 threshold=341
2021-09-11 08:46:51.003 [S2E:VERB] ::1 diid=50614 [ant#0] - starting TX in 19ms838us
2021-09-11 08:46:51.017 [___:INFO] lgw_start:850: --- IN
Opening SPI communication interface
Note: chip version is 0x10 (v1.0)
INFO: using legacy timestamp
INFO: LoRa Service modem: configuring preamble size to 8 symbols
Loading AGC fw for sx1250
Loading ARB fw
ARB: dual demodulation disabled for all SF
INFO: no temeprature sensor found on port 0x39
INFO: found temperature sensor on port 0x3B
lgw_start:1179: --- OUT
lgw_receive:1310: INFO: RSSI temperature offset applied: 1.574 dB (current temperature 35.7 C)
lgw_receive:1313: INFO: nb pkt found:1 left:0
lgw_receive:1310: INFO: RSSI temperature offset applied: 1.564 dB (current temperature 35.5 C)
lgw_receive:1313: INFO: nb pkt found:1 left:0
lgw_receive:1310: INFO: RSSI temperature offset applied: 1.567 dB (current temperature 35.6 C)
lgw_receive:1313: INFO: nb pkt found:1 left:0
lgw_send:1340: --- IN
lgw_send:1474: --- OUT
lgw_receive:1310: INFO: RSSI temperature offset applied: 1.574 dB (current temperature 35.7 C)
lgw_receive:1313: INFO: nb pkt found:1 left:0
lgw_send:1340: --- IN
2021-09-11 08:46:51.028 [S2E:INFO] TX ::1 diid=50614 [ant#0] - dntxed: 867.7MHz 16.0dBm ant#0(0) DR5 SF7/BW125 frame=6090170B26850A000352FF00..4698E443
2021-09-11 08:46:51.069 [S2E:DEBU] Tx done diid=50614
2021-09-11 08:46:52.889 [SYN:INFO] MCU/SX130X drift stats: min: +0.0ppm q50: +2.6ppm q80: -11.4ppm max: +12.9ppm - threshold q90: -11.9ppm
2021-09-11 08:46:52.890 [SYN:INFO] Mean MCU drift vs SX130X#0: 0.2ppm