Resolution of /SAPAPO/TSM207 errors in APO SNP planning

I am using APO V5.1 connected to a SAP ECC system.

When I CIF across a new product to APO and use it for the first time in SNP interactive planning I get error /SAPAPO/TSM207, because of missing time series objects.

The SAP recommendation in the error help text suggests to either re initialise the planning area, or to use pgm /SAPAPO/TS_LCM_PLOB_DELTA_SYNC. But I can only resolve the problem via the former approach (ie to re initialise the planning area). The use of /SAPAPO/TS_LCM_PLOB_DELTA_SYNC does not resolve the problem.

Is this expected behaviour?

What exactly is /SAPAPO/TS_LCM_PLOB_DELTA_SYNC designed to do?

If I look at help.sap.com for SCM 7 I see mention of a transaction /SAPAPO/TSINIT, which can be used as a 'delta' planning area re initialisation. But I do not see this transaction in APO V5.1 - so is this a new transaction in APO 7?

Thanks for any advice on this...