Lost device session

Hi,
i use your software for teltonika devices, the device is setted to permanent link for maintain the connection active. In the log i can see that the device send an ff every 30 seconds for maintain the connection. After some minutes the devices goes to unknown state in the traccar UI. In the previus versions if i send a coomand when a device is in unknown state it became online and the command was sended correctly. In the new version even if the devices continues to mantain the connection active sending ff when the devices goes to unknown state the software lose the device session and the commands are not sent, the software send the command only when after 1 hour more or less the device restart connection.

Can you provide logs showing ff messages?

2022-12-14 15:10:27  INFO: [Tbb187d12: teltonika > 194.88.243.118] 00000001
2022-12-14 15:10:27  INFO: [Tbb187d12] id: 350544503142492, time: 2022-12-14 15:07:23, lat: 37.69164, lon: 15.14574, course: 288.0
2022-12-14 15:10:29  INFO: [Tbb187d12] disconnected
2022-12-14 15:10:30  INFO: [T8d8d5875: teltonika < 18.196.213.123] ff
2022-12-14 15:10:34  INFO: [Td7b1df2f: teltonika < 18.196.213.123] ff
2022-12-14 15:10:36  INFO: [Tec9979ff] connected
2022-12-14 15:10:36  INFO: [Tec9979ff: teltonika < 194.88.243.118] 000f333530353434353033313432343932
2022-12-14 15:10:37  INFO: [Tec9979ff: teltonika > 194.88.243.118] 01
2022-12-14 15:11:00  INFO: [T8d8d5875: teltonika < 18.196.213.123] ff
2022-12-14 15:11:04  INFO: [Td7b1df2f: teltonika < 18.196.213.123] ff
2022-12-14 15:11:07  INFO: [Tec9979ff: teltonika < 194.88.243.118] ff
2022-12-14 15:11:29  INFO: [T8d8d5875: teltonika < 18.196.213.123] ff
2022-12-14 15:11:34  INFO: [Td7b1df2f: teltonika < 18.196.213.123] ff
2022-12-14 15:11:37  INFO: [Tec9979ff: teltonika < 194.88.243.118] ff
2022-12-14 15:11:59  INFO: [T8d8d5875: teltonika < 18.196.213.123] ff
2022-12-14 15:12:04  INFO: [Td7b1df2f: teltonika < 18.196.213.123] ff
2022-12-14 15:12:07  INFO: [Tec9979ff: teltonika < 194.88.243.118] ff
2022-12-14 15:12:29  INFO: [T8d8d5875: teltonika < 18.196.213.123] ff
2022-12-14 15:12:34  INFO: [Td7b1df2f: teltonika < 18.196.213.123] ff
2022-12-14 15:12:37  INFO: [Tec9979ff: teltonika < 194.88.243.118] ff
2022-12-14 15:12:59  INFO: [T8d8d5875: teltonika < 18.196.213.123] ff
2022-12-14 15:13:04  INFO: [Td7b1df2f: teltonika < 18.196.213.123] ff
2022-12-14 15:13:07  INFO: [Tec9979ff: teltonika < 194.88.243.118] ff
2022-12-14 15:13:30  INFO: [T8d8d5875: teltonika < 18.196.213.123] ff
2022-12-14 15:13:34  INFO: [Td7b1df2f: teltonika < 18.196.213.123] ff
2022-12-14 15:13:37  INFO: [Tec9979ff: teltonika < 194.88.243.118] ff
2022-12-14 15:14:00  INFO: [T8d8d5875: teltonika < 18.196.213.123] ff
2022-12-14 15:14:04  INFO: [Td7b1df2f: teltonika < 18.196.213.123] ff
2022-12-14 15:14:07  INFO: [Tec9979ff: teltonika < 194.88.243.118] ff
2022-12-14 15:14:32  INFO: [T8d8d5875: teltonika < 18.196.213.123] ff
2022-12-14 15:14:34  INFO: [Td7b1df2f: teltonika < 18.196.213.123] ff
2022-12-14 15:14:37  INFO: [Tec9979ff: teltonika < 194.88.243.118] ff
2022-12-14 15:15:01  INFO: [T8d8d5875: teltonika < 18.196.213.123] ff
2022-12-14 15:15:04  INFO: [Td7b1df2f: teltonika < 18.196.213.123] ff
2022-12-14 15:15:07  INFO: [Tec9979ff: teltonika < 194.88.243.118] ff
2022-12-14 15:15:31  INFO: [T8d8d5875: teltonika < 18.196.213.123] ff
2022-12-14 15:15:34  INFO: [Td7b1df2f: teltonika < 18.196.213.123] ff
2022-12-14 15:15:38  INFO: [Tec9979ff: teltonika < 194.88.243.118] ff
2022-12-14 15:16:00  INFO: [T8d8d5875: teltonika < 18.196.213.123] ff
2022-12-14 15:16:04  INFO: [Td7b1df2f: teltonika < 18.196.213.123] ff
2022-12-14 15:16:08  INFO: [Tec9979ff: teltonika < 194.88.243.118] ff
2022-12-14 15:16:30  INFO: [T8d8d5875: teltonika < 18.196.213.123] ff

this is the log of 5 minutes, actually 3 devices are sending messages, i took the messages from the last reconnection of 1 of the devices

This should solve the issue:

https://github.com/traccar/traccar/commit/64391161c1fb03bd9ff5ea30749b4e00230fa8aa

I've tried your fix and it seems to work, now the devices don't go in unknown state and remains online because the 0xff data is no longer ignored. I will try this for a couple of days, if i have problems i tell you.
Thank you very much!