SEEWORLD P5 (gt06) problems with traccar server decoder?

using Traccar 6.14.5, self-hosted. Device is a SEEWORLD P5 on port 5023. Device Model field is set to SEEWORLD.

The device logs in successfully and the server acknowledges it. The next packet it sends throws a decoder exception, the connection is closed, and the device reconnects and repeats.

log from traccar:

2026-07-29 13:40:41  INFO: [Tbb27c9ac] connected
2026-07-29 13:40:42  INFO: [Tbb27c9ac: gt06 < ...] 78780d010357956370796379000011950d0a
2026-07-29 13:40:42  INFO: [Tbb27c9ac: gt06 > ...] 787805010000c8550d0a
2026-07-29 13:40:43  INFO: [Tbb27c9ac: gt06 < ...] 787818a300000005321e020000000002584f000100060000008f920d0a
2026-07-29 13:40:43  WARN: [Tbb27c9ac] error - readerIndex(27) + length(3) exceeds writerIndex(29): UnpooledSlicedByteBuf(ridx: 27, widx: 29, cap: 29/29) - IndexOutOfBoundsException (... < Gt06ProtocolDecoder:388 < *:860 < *:1624 < ExtendedObjectDecoder:72 < ...)
2026-07-29 13:40:43  INFO: [Tbb27c9ac] disconnected

Has anybody else had the same problem? I am wondering if its decoder problem or something else?

I have asked SEEWORLD if there is special protocol documentation for this P5 device and will post it here if they provide it.

These links provide more detailed logs:

https://drive.google.com/file/d/1oIkJceCzNviEuO1bhhn1ftO1gQpbsGYt/view?usp=sharing
https://drive.google.com/file/d/1tzoLYU3B30QQQ6noHLV5CfoD1qd2ixOb/view?usp=sharing

Do you have the protocol documentation?

not currently, I asked SEEWORLD for it and just waiting for their reply, I can share it here if/when I get it

Yes please share once you have it.