Ebusd messages decoding

[wrongisthenewright]

Hi all,
I have a working ebusd setup. the package is running on a docker, with a wifi adapter installed near my boiler/heatpump. My HVAC is an Ariston system, so non standard ebusd protocol (they've dubbed it BusBridgenet(R)) luckily the physical layer is the same so the "only" problem is related to the decoding of the messages.
My system is now able to sniff the bus traffic, decode many messages that I send via MQTT to HA for record and reporting.
I've been able to decode many messages, but at the moment I'm struggling to understand why ebusd cannot decode some messages that it is correctly able to read, as an example, in my CSV I've got this line

r,test_heatpump,unkn_info12,Unknown Info,13,fe,2010,0591,0591_UIN,m,UIN,,,,,m,IGN:2,,,,0691_UIN,m,UIN,,,,,m,IGN:2,,,,0791_UIN,m,UIN

ebusd correctly trap the message and start decoding, as shown by ebusdctl grab result all command output:

13fe20100c059100000691000007910000 = 479: test_heatpump unkn_info12

this second line, instead

r,test_sensys,unkn_info15,Unknown Info,13,fe,2010,c64b,c64b_UIN,m,UIN,,,,,m,IGN:2,,,,c94b_UIN,m,UIN

didn't get matched and decoded

13fe201008c64b0800c94b0200 = 553

Before opening an issue I'd like to know if I'm messing/missing something.

TY