The Ericsson BP range of PBXs has a Call handling setting that allows it to select a different channel number that what is reported on the SMDR.
Since the SMDR is used to link the call information to the recorded trunks on the voice recording software, then details must always match.
Please ensure that the "B-channel selection mode [1913]" is set to option "2: Exclusive selection (linked to trunk individual)".
This will ensure that the PRI/BRI channel that is reported on the SMDR will match what is actually used on the trunk. Without this setting your trunk channel details that is reported on the SMDR will have a different value than the actual trunk channel that is used on the service provider side.