ISDP entry on HPE 1920S log

Hi, folks!

We are having the messages shown below in an HPE 1920S 24G 2SFP(JL381A)

System description:  HPE OfficeConnect Switch 1920S 24G 2SFP JL381A, PD.01.05, Linux 3.6.5, U-Boot 2012.10-00118 (Oct 11 2016 - 15:39:54

Nov 5 11:55:02 192.168.1.2 ISDP[isdpTask]: isdp_control.c(386) 34378 %% ISDP entry add failed on interface 24.
Nov 5 11:55:02 192.168.1.2 ISDP[isdpTask]: isdp_control.c(418) 34379 %% ISDP entry add failed on interface 24.
Nov 5 11:55:04 192.168.1.2 ISDP[isdpTask]: isdp_control.c(386) 34380 %% ISDP entry add failed on interface 24.
Nov 5 11:55:04 192.168.1.2 ISDP[isdpTask]: isdp_control.c(418) 34381 %% ISDP entry add failed on interface 24.
Nov 5 11:55:10 192.168.1.2 ISDP[isdpTask]: isdp_control.c(386) 34382 %% ISDP entry add failed on interface 24.
Nov 5 11:55:10 192.168.1.2 ISDP[isdpTask]: isdp_control.c(418) 34383 %% ISDP entry add failed on interface 24.
Nov 5 13:07:52 192.168.1.2 ISDP[dtlTask]: isdp_txrx.c(169) 34384 %% Foreign pdu on interface 24

Port 24 is part of a trunk with other 3 ports.

Any clew about the meaning? I didn't find anything on manuals or HPE forums.

Thanks.

Pardon my English.